Tree-based Label Dependency Topic Models - Nguyen, V A; Jordan Boyd-Graber; Chang, J; Resnik, P (cs.umd.edu)
Abstract Multi-labeled corpora, where each document is tagged with a set of labels, are ubiquitous. When the number of unique labels in the dataset is large, there are naturally some dependencies among the labels. In this paper, we propose TREELAD—a ...

Rapid, quantitative therapeutic screening for Alzheimer's enzymes enabled by optimal signal transduction with transistors - Le, Son T.; Morris, Michelle A.; Cardone, Antonio; Guros, Nicholas B.; Klauda, Jeffery B.; Sperling, Brent A.; Richter, Curt A.; Pant, Harish C.; Balijepalli, Arvind (The Analyst, 2020)

Metagenome sequencing-based strain-level and functional characterization of supragingival microbiome associated with dental caries in children - Al-Hebshi, Nezar Noor; Baraniya, Divyashri; Chen, Tsute; Hill, Jennifer; Puri, Sumant; Tellez, Marisol; Hassan, Nur A.; Rita R Colwell; Ismail, Amid (Journal of Oral Microbiology, 2019)
Studies of the microbiome associated with dental caries have largely relied on 16S rRNA sequence analysis, which is associated with PCR biases, low taxonomic resolution, and inability to accurately study functions. Here, we employed whole metagenome shotgun sequencing, coupled with high-resolution analysis algorithm, to analyze supragingival microbiomes from 30 children with or without dental caries. A total of 726 bacterial strains belonging to 406 species, in addition to 34 bacteriophages were identified. A core bacteriome was identified at the species and strain levels. Species of Prevotella, Veillonella, as yet unnamed Actinomyces, and Atopobium showed strongest association with caries; Streptococcus sp. AS14 and Leptotrichia sp. Oral taxon 225, among others, were overabundant in caries-free. For several species, the association was strain-specific. Furthermore, for some species, e.g. Streptococcus mitis and Streptococcus sanguinis, sister strains showed differential associations. Noteworthy, associations were also identified for phages: Streptococcus phage M102 with caries and Haemophilus phage HP1 with caries-free. Functionally, potentially relevant features were identified including urate, vitamin K2, and polyamine biosynthesis in association with caries; and three deiminases and lactate dehydrogenase with health. The results demonstrate new associations between the microbiome and dental caries at the strain and functional levels that need further investigation.

Quantum Capacitance-Limited MoS2 Biosensors Enable Remote Label-Free Enzyme Measurements - Le, Son T; Guros, Nicholas B; Bruce, Robert C; Cardone, Antonio; Amin, Niranjana D; Zhang, Siyuan; Klauda, Jeffery; Pant, Harish C; Richter, Curt A; Balijepalli, Arvind (Nanoscale, 2019)

Biofilms Comprise a Component of the Annual Cycle of Vibrio cholerae in the Bay of Bengal Estuary - Sultana, Marzia; Nusrin, Suraia; Hasan, Nur A.; Sadique, Abdus; Ahmed, Kabir U.; Islam, Atiqul; Hossain, Anwar; Longini, Ira; Nizam, Azhar; Huq, Anwar; Siddique, Abul K.; Sack, David A.; et al. (mBio, 2018)
Vibrio cholerae, an estuarine bacterium, is the causative agent of cholera, a severe diarrheal disease that demonstrates seasonal incidence in Bangladesh. In an extensive study of V. cholerae occurrence in a natural aquatic environment, water and plankton samples were collected biweekly between December 2005 and November 2006 from Mathbaria, an estuarine village of Bangladesh near the mangrove forests of the Sundarbans. Toxigenic V. cholerae exhibited two seasonal growth peaks, one in spring (March to May) and another in autumn (September to November), corresponding to the two annual seasonal outbreaks of cholera in this region. The total numbers of bacteria determined by heterotrophic plate count (HPC), representing culturable bacteria, accounted for 1% to 2.7% of the total numbers obtained using acridine orange direct counting (AODC). The highest bacterial culture counts, including toxigenic V. cholerae, were recorded in the spring. The direct fluorescent antibody (DFA) assay was used to detect V. cholerae O1 cells throughout the year, as free-living cells, within clusters, or in association with plankton. V. cholerae O1 varied significantly in morphology, appearing as distinctly rod-shaped cells in the spring months, while small coccoid cells within thick clusters of biofilm were observed during interepidemic periods of the year, notably during the winter months. Toxigenic V. cholerae O1 was culturable in natural water during the spring when the temperature rose sharply. The results of this study confirmed biofilms to be a means of persistence for bacteria and an integral component of the annual life cycle of toxigenic V. cholerae in the estuarine environment of Bangladesh.

Characterization of the Microbiome at the World’s Largest Potable Water Reuse Facility - Stamps, Blake W.; Leddy, Menu B.; Plumlee, Megan H.; Hasan, Nur A.; Rita R Colwell; Spear, John R. (Frontiers in Microbiology, 2018)
Conventional water resources are not sufficient in many regions to meet the needs of growing populations. Due to cyclical weather cycles, drought, and climate change, water stress has increased worldwide including in Southern California, which serves as a model for regions that integrate reuse of wastewater for both potable and non-potable use. The Orange County Water District (OCWD) Advanced Water Purification Facility (AWPF) is a highly engineered system designed to treat and produce up to 100 million gallons per day (MGD) of purified water from a municipal wastewater source for potable reuse. Routine facility microbial water quality analysis is limited to standard indicators at this and similar facilities. Given recent advances in high throughput DNA sequencing techniques, complete microbial profiling of communities in water samples is now possible. By using 16S/18S rRNA gene sequencing, metagenomic and metatranscriptomic sequencing coupled to a highly accurate identification method along with 16S rRNA gene qPCR, we describe a detailed view of the total microbial community throughout the facility. The total bacterial load of the water at stages of the treatment train ranged from 3.02 × 106 copies in source, unchlorinated wastewater feed to 5.49 × 101 copies of 16S rRNA gene/mL after treatment (consisting of microfiltration, reverse osmosis, and ultraviolet/advanced oxidation). Microbial diversity and load decreased by several orders of magnitude after microfiltration and reverse osmosis treatment, falling to almost non-detectable levels that more closely resembled controls of molecular grade laboratory water than the biomass detected in the source water. The presence of antibiotic resistance genes and viruses was also greatly reduced. Overall, system design performance was achieved, and comprehensive microbial community analysis was found to enable a more complete characterization of the water/wastewater microbial signature. Keywords: water reuse, pathogens, water purification, metatranscriptomics, metagenomics

Comparison of Infant Gut and Skin Microbiota, Resistome and Virulome Between Neonatal Intensive Care Unit (NICU) Environments - Hourigan, Suchitra K.; Subramanian, Poorani; Hasan, Nur A.; Ta, Allison; Klein, Elisabeth; Chettout, Nassim; Huddleston, Kathi; Deopujari, Varsha; Levy, Shira; Baveja, R; Clemency, Nicole C.; Baker, Robin L.; et al. (Frontiers in Microbiology, 2018)

Deep-learning-assisted Volume Visualization - Cheng, Hsueh-Chien; Cardone, Antonio; Jain, Somay; Krokos, Eric; Narayan, Kedar; Subramaniam, Sriram; Varshney, Amitabh (IEEE Transactions on Visualization and Computer Graphics, 2018)

Distinct consequences of amoxicillin and ertapenem exposure in the porcine gut microbiome - Connelly, Sheila; Subramanian, Poorani; Hasan, Nur A.; Rita R Colwell; Kaleko, Michael (Anaerobe, 2018)

Environmental and hydroclimatic factors influencing Vibrio populations in the estuarine zone of the Bengal delta - Neogi, Sucharit; Rubin, Lara; Alam, Munirul; Harder, Jens; Yamasaki, Shinji; Rita R Colwell (Environmental Monitoring and Assessment, 2018)
The objective of this study was to determine environmental parameters driving Vibrio populations in the estuarine zone of the Bengal delta. Spatio-temporal data were collected at river estuary, mangrove, beach, pond, and canal sites. Effects of salinity, tidal amplitude, and a cyclone and tsunami were included in the study. Vibrio population shifts were found to be correlated with tide-driven salinity and suspended particulate matter (SPM). Increased abundance of Vibrio spp. in surface water was observed after a cyclone, attributed to re-suspension of benthic particulate organic carbon (POC), and increased availability of chitin and dissolved organic carbon (DOC). Approximately a two log10 increase in the (p < 0.05) number of Vibrio spp. was observed in < 20 μm particulates, compared with microphytoplankton (20–60 μm) and zooplankton > 60 μm fractions. Benthic and suspended sediment comprised a major reservoir of Vibrio spp. Results of microcosm experiments showed enhanced growth of vibrios was related to concentration of organic matter in SPM. It is concluded that SPM, POC, chitin, and salinity significantly influence abundance and distribution of vibrios in the Bengal delta estuarine zone. Keywords Vibrio Salinity Cyclone Tide Chitin Sediment dynamics

High-Throughput DNA Sequencing To Profile Microbial Water Quality Of Potable Reuse - Menu B. Leddy; Megan H. Plumlee; Rose S. Kantor; Kara L. Nelson; Scott E. Miller; Lauren C. Kennedy; Blake W. Stamps; John R. Spear; Nur A. Hasan; Rita R Colwell (2018)

Interpolation-Based Gray-Level Co-Occurrence Matrix Computation for Texture Directionality Estimation - Marcin Kociolek; Mary Brady; Peter Bajcsy; Cardone, Antonio (IEEE 22nd Signal Processing Algorithms, Architectures, Arrangements, and Applications Conference, 2018)
A novel interpolation-based model for the computation of the Gray Level Co-occurrence Matrix (GLCM) is presented. The model enables GLCM computation for any real valued angles and offsets, as opposed to the traditional, lattice-based model. A texture directionality estimation algorithm is defined using the GLCM-derived correlation feature. The robustness of the algorithm with respect to image blur and additive Gaussian noise is evaluated. It is concluded that directionality estimation is robust to image blur and low noise levels. For high noise levels, the mean error increases but remains bounded. The performance of the directionality estimation algorithm is illustrated on fluorescence microscopy images of fibroblast cells. The algorithm was implemented in C++ and the source code is available in an openly accessible repository.

A Metagenomic Approach to Evaluating Surface Water Quality in Haiti - Roy, Monika; Arnaud, Jean; Jasmin, Paul; Hamner, Steve; Hasan, Nur; Rita R Colwell; Ford, Timothy (International Journal of Environmental Research and Public Health, 2018)
The cholera epidemic that occurred in Haiti post-earthquake in 2010 has resulted in over 9000 deaths during the past eight years. Currently, morbidity and mortality rates for cholera have declined, but cholera cases still occur on a daily basis. One continuing issue is an inability to accurately predict and identify when cholera outbreaks might occur. To explore this surveillance gap, a metagenomic approach employing environmental samples was taken. In this study, surface water samples were collected at two time points from several sites near the original epicenter of the cholera outbreak in the Central Plateau of Haiti. These samples underwent whole genome sequencing and subsequent metagenomic analysis to characterize the microbial community of bacteria, fungi, protists, and viruses, and to identify antibiotic resistance and virulence associated genes. Replicates from sites were analyzed by principle components analysis, and distinct genomic profiles were obtained for each site. Cholera toxin converting phage was detected at one site, and Shiga toxin converting phages at several sites. Members of the Acinetobacter family were frequently detected in samples, including members implicated in waterborne diseases. These results indicate a metagenomic approach to evaluating water samples can be useful for source tracking and the surveillance of pathogens such as Vibrio cholerae over time, as well as for monitoring virulence factors such as cholera toxin.

Occurrence of Vibrio cholerae in water reservoirs of Burkina Faso - Kaboré, Saidou; Cecchi, Philippe; Mosser, Thomas; Toubiana, Mylène; Traoré, Oumar; Ouattara, Aboubakar S.; Traoré, Alfred S.; Barro, Nicolas; Rita R Colwell; Monfort, Patrick (Research in Microbiology, 2018)
Africa is currently an important region in which cholera epidemics occur. Little is known about the presence of Vibrio cholerae in freshwater bodies in Africa. There are ca. 1700 lakes and reservoirs in Burkina Faso, most of which have been built within recent decades to secure water resources. The purpose of this study was to investigate the presence of V. cholerae in the water of reservoirs, using the most-probable-number polymerase chain reaction. Results showed that V. cholerae could be detected in water samples collected from 14 of 39 sampled reservoirs. The concentrations varied from 0 MPN/l to more than 1100 MPN/l. Fifty strains of V. cholerae isolated on CHROMagar™ vibrio were identified as V. cholerae non-O1/non-O139, none of which carried the ctxA gene. A significant positive correlation was found between the presence of V. cholerae in the reservoirs and both alkaline pH and phytoplankton biomass. V. cholerae was present in significantly higher numbers in reservoirs of urban areas than in rural areas. Since V. cholerae non-O1/non-O139 has been shown to be a causative agent of endemic diarrheal outbreaks, their presence in Burkina Faso reservoirs suggests they may play a role in gastroenteritis in that country.

Satellites and Cell Phones Form a Cholera Early-Warning System - Akanda, Ali; Aziz, Sonia; Jutla, Antarpreet; Huq, Anwar; Alam, Munirul; Ahsan, Gias; Rita R Colwell (Eos, 2018)

Spores and soil from six sides: interdisciplinarity and the environmental biology of anthrax (Bacillus anthracis) - Carlson, Colin J.; Getz, Wayne M.; Kausrud, Kyrre L.; Cizauskas, Carrie A.; Blackburn, Jason K.; Bustos Carrillo, Fausto A.; Rita R Colwell; Easterday, W. Ryan; Ganz, Holly H.; Kamath, Pauline L.; Økstad, Ole A.; Turner, Wendy C.; et al. (Biological Reviews, 2018)
Environmentally transmitted diseases are comparatively poorly understood and managed, and their ecology is particularly understudied. Here we identify challenges of studying environmental transmission and persistence with a six‐sided interdisciplinary review of the biology of anthrax (Bacillus anthracis). Anthrax is a zoonotic disease capable of maintaining infectious spore banks in soil for decades (or even potentially centuries), and the mechanisms of its environmental persistence have been the topic of significant research and controversy. Where anthrax is endemic, it plays an important ecological role, shaping the dynamics of entire herbivore communities. The complex eco‐epidemiology of anthrax, and the mysterious biology of Bacillus anthracis during its environmental stage, have necessitated an interdisciplinary approach to pathogen research. Here, we illustrate different disciplinary perspectives through key advances made by researchers working in Etosha National Park, a long‐term ecological research site in Namibia that has exemplified the complexities of the enzootic process of anthrax over decades of surveillance. In Etosha, the role of scavengers and alternative routes (waterborne transmission and flies) has proved unimportant relative to the long‐term persistence of anthrax spores in soil and their infection of herbivore hosts. Carcass deposition facilitates green‐ups of vegetation to attract herbivores, potentially facilitated by the role of anthrax spores in the rhizosphere. The underlying seasonal pattern of vegetation, and herbivores' immune and behavioural responses to anthrax risk, interact to produce regular ‘anthrax seasons’ that appear to be a stable feature of the Etosha ecosystem. Through the lens of microbiologists, geneticists, immunologists, ecologists, epidemiologists, and clinicians, we discuss how anthrax dynamics are shaped at the smallest scale by population genetics and interactions within the bacterial communities up to the broadest scales of ecosystem structure. We illustrate the benefits and challenges of this interdisciplinary approach to disease ecology, and suggest ways anthrax might offer insights into the biology of other important pathogens. Bacillus anthracis, and the more recently emerged Bacillus cereus biovar anthracis, share key features with other environmentally transmitted pathogens, including several zoonoses and panzootics of special interest for global health and conservation efforts. Understanding the dynamics of anthrax, and developing interdisciplinary research programs that explore environmental persistence, is a critical step forward for understanding these emerging threats.

Virulence-Related Genes Identified from the Genome Sequence of the Non-O1/Non-O139 Vibrio cholerae Strain VcN1, Isolated from Dhaka, Bangladesh - Hossain, Maqsud; Alam, Munirul; Khaleque, Abdul; Islam, Sohidul; Sadique, Abdus; Khan, Nayeim; Halim, Zahra; Sarker, Mrinmoy; El-Sayed, Najib M.; Huq, Anwar; Ahsan, Gias Uddin; Rita R Colwell (Genome Announcements, 2018)
We report here the first draft genome sequence of the non-O1/non-O139 Vibrio cholerae strain VcN1, isolated from Dhaka, Bangladesh. The data submitted to GenBank for this strain will contribute to advancing our understanding of this environmentally disseminated bacterium, including its virulence and its evolution as an important pathogen.

Application of a paper based device containing a new culture medium to detect Vibrio cholerae in water samples collected in Haiti - Briquaire, Romain; Rita R Colwell; Boncy, Jacques; Rossignol, Emmanuel; Dardy, Aline; Pandini, Isabelle; Villeval, François; Machuron, Jean-Louis; Huq, Anwar; Rashed, Shah; Vandevelde, Thierry; Rozand, Christine (Journal of Microbiological Methods, 2017)

Assessment of Risk of Cholera in Haiti following Hurricane Matthew - Huq, Anwar; Anwar, Rifat; Rita R Colwell; McDonald, Michael D.; Khan, Rakib; Jutla, Antarpreet; Akanda, Shafqat (The American Journal of Tropical Medicine and Hygiene, 2017)
Damage to the inferior and fragile water and sanitation infrastructure of Haiti after Hurricane Matthew has created an urgent public health emergency in terms of likelihood of cholera occurring in the human population. Using satellite-derived data on precipitation, gridded air temperature, and hurricane path and with information on water and sanitation (WASH) infrastructure, we tracked changing environmental conditions conducive for growth of pathogenic vibrios. Based on these data, we predicted and validated the likelihood of cholera cases occurring past hurricane. The risk of cholera in the southwestern part of Haiti remained relatively high since November 2016 to the present. Findings of this study provide a contemporary process for monitoring ground conditions that can guide public health intervention to control cholera in human population by providing access to vaccines, safe WASH facilities. Assuming current social and behavioral patterns remain constant, it is recommended that WASH infrastructure should be improved and considered a priority especially before 2017 rainy season.

Beyond cost-effectiveness: Using systems analysis for infectious disease preparedness - Phelps, Charles; Madhavan, Guruprasad; Rappuoli, Rino; Rita R Colwell; Fineberg, Harvey (Vaccine, 2017)
Until the recent outbreaks, Ebola vaccines ranked low in decision makers’ priority lists based on cost-effectiveness analysis and (or) corporate profitability. Despite a relatively small number of Ebola-related cases and deaths (compared to other causes), Ebola vaccines suddenly leapt to highest priority among international health agencies and vaccine developers. Clearly, earlier cost-effectiveness analyses badly missed some factors affecting real world decisions. Multi-criteria systems analysis can improve evaluation and prioritization of vaccine development and also of many other health policy and investment decisions. Neither cost-effectiveness nor cost-benefit analysis can capture important aspects of problems such as Ebola or the emerging threat of Zika, especially issues of inequality and disparity—issues that dominate the planning of many global health and economic organizations. Cost-benefit analysis requires assumptions about the specific value of life—an idea objectionable to many analysts and policy makers. Additionally, standard cost-effectiveness calculations cannot generally capture effects on people uninfected with Ebola for example, but nevertheless affected through such factors as contagion, herd immunity, and fear of dread disease, reduction of travel and commerce, and even the hope of disease eradication. Using SMART Vaccines, we demonstrate how systems analysis can visibly include important “other factors” and more usefully guide decision making and beneficially alter priority setting processes.

A Bioinformatics 3D Cellular Morphotyping Strategy for Assessing Biomaterial Scaffold Niches - Florczyk, Stephen J.; Simon, Mylene; Juba, Derek; Pine, P. Scott; Sarkar, Sumona; Chen, Desu; Baker, Paula J.; Bodhak, Subhadip; Cardone, Antonio; Brady, Mary C.; Bajcsy, Peter; Simon, Carl G. (ACS Biomaterials Science & Engineering, 2017)

Characterization of Microbial Signatures From Advanced Treated Wastewater Biofilms - Leddy, Menu B.; Hasan, Nur A.; Subramanian, Poorani; Heberling, Colin; Cotruvo, Joseph; Rita R Colwell (Journal - American Water Works Association, 2017)
Next‐generation sequencing (NGS) and metagenomics were used to identify microbial communities in biofilms of microfiltration (MF) and reverse osmosis (RO) membranes in an advanced water purification facility (AWPF) that treats municipal wastewater to produce potable quality water. Secondary treated wastewater effluent is the source of influent to the AWPF treatment train and was also characterized by NGS. Results show low bacterial diversity in biofilms obtained from the feed‐side surfaces of MF and RO membranes. Microbial communities and antibiotic resistance genes (ARGs) in the RO biofilm were compared with those of the MF and influent, revealing lower abundance of bacterial species and ARGs in the RO biofilm than in the other samples. Opportunistic pathogens were detected in all samples; however, indicator bacteria, viruses, and bacteriophages were not detected in the RO biofilm. It is concluded that NGS has great potential for improved detection and characterization of microbial communities in biofilms that form on AWPF MF and RO membranes.

Characterization of Pathogenic Vibrio parahaemolyticus from the Chesapeake Bay, Maryland - Chen, Arlene J.; Hasan, Nur A.; Haley, Bradd J.; Taviani, Elisa; Tarnowski, Mitch; Brohawn, Kathy; Johnson, Crystal N.; Rita R Colwell; Huq, Anwar (Frontiers in Microbiology, 2017)

Characterization of Two Cryptic Plasmids Isolated in Haiti from Clinical Vibrio cholerae Non-O1/Non-O139 - Ceccarelli, Daniela; Garriss, Genevieve; Choi, Seon Y.; Hasan, Nur A.; Stepanauskas, Ramunas; Pop, Mihai; Huq, Anwar; Rita R Colwell (Frontiers in Microbiology, 2017)

Comparative genomic analysis and characterization of incompatibility group FIB plasmid encoded virulence factors of Salmonella enterica isolated from food sources - Khajanchi, Bijay K.; Hasan, Nur A.; Choi, Seon Young; Han, Jing; Zhao, Shaohua; Rita R Colwell; Cerniglia, Carl E.; Foley, Steven L. (BMC Genomics, 2017)
BACKGROUND: The degree to which the chromosomal mediated iron acquisition system contributes to virulence of many bacterial pathogens is well defined. However, the functional roles of plasmid encoded iron acquisition systems, specifically Sit and aerobactin, have yet to be determined for Salmonella spp. In a recent study, Salmonella enterica strains isolated from different food sources were sequenced on the Illumina MiSeq platform and found to harbor the incompatibility group (Inc) FIB plasmid. In this study, we examined sequence diversity and the contribution of factors encoded on the IncFIB plasmid to the virulence of S. enterica. RESULTS: Whole genome sequences of seven S. enterica isolates were compared to genomes of serovars of S. enterica isolated from food, animal, and human sources. SeqSero analysis predicted that six strains were serovar Typhimurium and one was Heidelberg. Among the S. Typhimurium strains, single nucleotide polymorphism (SNP)-based phylogenetic analyses revealed that five of the isolates clustered as a single monophyletic S. Typhimurium subclade, while one of the other strains branched with S. Typhimurium from a bovine source. DNA sequence based phylogenetic diversity analyses showed that the IncFIB plasmid-encoded Sit and aerobactin iron acquisition systems are conserved among bacterial species including S. enterica. The IncFIB plasmid was transferred to an IncFIB plasmid deficient strain of S. enterica by conjugation. The transconjugant SE819::IncFIB persisted in human intestinal epithelial (Caco-2) cells at a higher rate than the recipient SE819. Genes of the Sit and aerobactin operons in the IncFIB plasmid were differentially expressed in iron-rich and iron-depleted growth media. CONCLUSIONS: Minimal sequence diversity was detected in the Sit and aerobactin operons in the IncFIB plasmids present among different bacterial species, including foodborne Salmonella strains. IncFIB plasmid encoded factors play a role during infection under low-iron conditions in host cells.

Comparative Genomics of Escherichia coli Isolated from Skin and Soft Tissue and Other Extraintestinal Infections - Ranjan, Amit; Shaik, Sabiha; Nandanwar, Nishant; Hussain, Arif; Tiwari, Sumeet K.; Semmler, Torsten; Jadhav, Savita; Wieler, Lothar H.; Alam, Munirul; Rita R Colwell; Ahmed, Niyaz (mBio, 2017)
Escherichia coli, an intestinal Gram-negative bacterium, has been shown to be associated with a variety of diseases in addition to intestinal infections, such as urinary tract infections (UTIs), meningitis in neonates, septicemia, skin and soft tissue infections (SSTIs), and colisepticemia. Thus, for nonintestinal infections, it is categorized as extraintestinal pathogenic E. coli (ExPEC). It is also an opportunistic pathogen, causing cross infections, notably as an agent of zoonotic diseases. However, comparative genomic data providing functional and genetic coordinates for ExPEC strains associated with these different types of infections have not proven conclusive. In the study reported here, ExPEC E. coli isolated from SSTIs was characterized, including virulence and drug resistance profiles, and compared with isolates from patients suffering either pyelonephritis or septicemia. Results revealed that the majority of the isolates belonged to two pathogenic phylogroups, B2 and D. Approximately 67% of the isolates were multidrug resistant (MDR), with 85% producing extended-spectrum beta-lactamase (ESBL) and 6% producing metallo-beta-lactamase (MBL). The blaCTX-M-15 genotype was observed in at least 70% of the E. coli isolates in each category, conferring resistance to an extended range of beta-lactam antibiotics. Whole-genome sequencing and comparative genomics of the ExPEC isolates revealed that two of the four isolates from SSTIs, NA633 and NA643, belong to pandemic sequence type ST131, whereas functional characteristics of three of the ExPEC pathotypes revealed that they had equal capabilities to form biofilm and were resistant to human serum. Overall, the isolates from a variety of ExPEC infections demonstrated similar resistomes and virulomes and did not display any disease-specific functional or genetic coordinates. IMPORTANCE Infections caused by extraintestinal pathogenic E. coli (ExPEC) are of global concern as they result in significant costs to health care facilities management. The recent emergence of a multidrug-resistant pandemic clone, Escherichia coli ST131, is of primary concern as a global threat. In developing countries, such as India, skin and soft tissue infections (SSTIs) associated with E. coli are marginally addressed. In this study, we employed both genomic analysis and phenotypic assays to determine relationships, if any, among the ExPEC pathotypes. Similarity between antibiotic resistance and virulence profiles was observed, ST131 isolates from SSTIs were reported, and genomic similarities among strains isolated from different disease conditions were detected. This study provides functional molecular infection epidemiology insight into SSTI-associated E. coli compared with ExPEC pathotypes.

Comprehensive benchmarking and ensemble approaches for metagenomic classifiers - McIntyre, Alexa B. R.; Ounit, Rachid; Afshinnekoo, Ebrahim; Prill, Robert J.; Hénaff, Elizabeth; Alexander, Noah; Minot, Samuel S.; Danko, David; Foox, Jonathan; Ahsanuddin, Sofia; Tighe, Scott; Hasan, Nur A.; et al. (Genome Biology, 2017)

CRISPR-Cas and Contact-Dependent Secretion Systems Present on Excisable Pathogenicity Islands with Conserved Recombination Modules - Carpenter, Megan R.; Kalburge, Sai S.; Borowski, Joseph D.; Peters, Molly C.; Rita R Colwell; Boyd, E. Fidelma (Journal of Bacteriology, 2017)
Pathogenicity islands (PAIs) are mobile integrated genetic elements that contain a diverse range of virulence factors. PAIs integrate into the host chromosome at a tRNA locus that contains their specific bacterial attachment site, attB, via integrase-mediated site-specific recombination generating attL and attR sites. We identified conserved recombination modules (integrases and att sites) previously described in choleragenic Vibrio cholerae PAIs but with novel cargo genes. Clustered regularly interspaced short palindromic repeat (CRISPR)-associated proteins (Cas proteins) and a type VI secretion system (T6SS) gene cluster were identified at the Vibrio pathogenicity island 1 (VPI-1) insertion site in 19 V. cholerae strains and contained the same recombination module. Two divergent type I-F CRISPR-Cas systems were identified, which differed in Cas protein homology and content. The CRISPR repeat sequence was identical among all V. cholerae strains, but the CRISPR spacer sequences and the number of spacers varied. In silico analysis suggests that the CRISPR-Cas systems were active against phages and plasmids. A type III secretion system (T3SS) was present in 12 V. cholerae strains on a 68-kb island inserted at the same tRNA-serine insertion site as VPI-2 and contained the same recombination module. Bioinformatics analysis showed that two divergent T3SSs exist among the strains examined. Both the CRISPR and T3SS islands excised site specifically from the bacterial chromosome as complete units, and the cognate integrases were essential for this excision. These data demonstrated that identical recombination modules that catalyze integration and excision from the chromosome can acquire diverse cargo genes, signifying a novel method of acquisition for both CRISPR-Cas systems and T3SSs.

Deep-learning-assisted visualization for live-cell images - Hsueh-Chien Cheng; Cardone, Antonio; Krokos, Eric; Stoica, Bogdan; Faden, Alan; Varshney, Amitabh (IEEE International Conference on Image Processing, 2017)
Analyzing live-cell images is particularly challenging because cells move at the same time they undergo systematic changes. Visually inspecting live-cell images therefore involves simultaneously tracking individual cells and detecting relevant spatio-temporal changes. The high cognitive burden of such a complex task makes this kind of analysis inefficient and error-prone. In this paper we describe a deep-learning-assisted visualization based on automatically derived high-level features to identify target cell changes in live-cell images. Applying a novel user-mediated color assignment scheme that maps abstract features into corresponding colors, we create color-based visual annotations that facilitate visual reasoning and analysis of complex time varying live-cell imagery datasets. The visual representations can be used to study temporal changes in cells, such as the morphological changes in cell at various stages of life cycle.
Keywords: deep learning; live-cell images; Visualization

Genomic Methods and Microbiological Technologies for Profiling Novel and Extreme Environments for the Extreme Microbiome Project (XMP) - Tighe, Scott; Afshinnekoo, Ebrahim; Rock, Tara M.; McGrath, Ken; Alexander, Noah; McIntyre, Alexa; Ahsanuddin, Sofia; Bezdan, Daniela; Green, Stefan J.; Joye, Samantha; Stewart Johnson, Sarah; Baldwin, Don A.; et al. (Journal of Biomolecular Techniques : JBT, 2017)
The Extreme Microbiome Project (XMP) is a project launched by the Association of Biomolecular Resource Facilities Metagenomics Research Group (ABRF MGRG) that focuses on whole genome shotgun sequencing of extreme and unique environments using a wide variety of biomolecular techniques. The goals are multifaceted, including development and refinement of new techniques for the following: 1) the detection and characterization of novel microbes, 2) the evaluation of nucleic acid techniques for extremophilic samples, and 3) the identification and implementation of the appropriate bioinformatics pipelines. Here, we highlight the different ongoing projects that we have been working on, as well as details on the various methods we use to characterize the microbiome and metagenome of these complex samples. In particular, we present data of a novel multienzyme extraction protocol that we developed, called Polyzyme or MetaPolyZyme. Presently, the XMP is characterizing sample sites around the world with the intent of discovering new species, genes, and gene clusters. Once a project site is complete, the resulting data will be publically available. Sites include Lake Hillier in Western Australia, the “Door to Hell” crater in Turkmenistan, deep ocean brine lakes of the Gulf of Mexico, deep ocean sediments from Greenland, permafrost tunnels in Alaska, ancient microbial biofilms from Antarctica, Blue Lagoon Iceland, Ethiopian toxic hot springs, and the acidic hypersaline ponds in Western Australia.

Hydroclimatic sustainability assessment of changing climate on cholera in the Ganges-Brahmaputra basin - Nasr-Azadani, Fariborz; Khan, Rakibul; Rahimikollu, Javad; Unnikrishnan, Avinash; Akanda, Ali; Alam, Munirul; Huq, Anwar; Jutla, Antarpreet; Rita R Colwell (Advances in Water Resources, 2017)
The association of cholera and climate has been extensively documented. However, determining the effects of changing climate on the occurrence of disease remains a challenge. Bimodal peaks of cholera in Bengal Delta are hypothesized to be linked to asymmetric flow of the Ganges and Brahmaputra rivers. Spring cholera is related to intrusion of bacteria-laden coastal seawater during low flow seasons, while autumn cholera results from cross-contamination of water resources when high flows in the rivers cause massive inundation. Coarse resolution of General Circulation Model (GCM) output (usually at 100 – 300 km)cannot be used to evaluate variability at the local scale(10–20 km),hence the goal of this study was to develop a framework that could be used to understand impacts of climate change on occurrence of cholera. Instead of a traditional approach of downscaling precipitation, streamflow of the two rivers was directly linked to GCM outputs, achieving reasonable accuracy (R2 = 0.89 for the Ganges and R2 = 0.91 for the Brahmaputra)using machine learning algorithms (Support Vector Regression-Particle Swarm Optimization). Copula methods were used to determine probabilistic risks of cholera under several discharge conditions. Key results, using model outputs from ECHAM5, GFDL, andHadCM3for A1B and A2 scenarios, suggest that the combined low flow of the two rivers may increase in the future, with high flows increasing for first half of this century, decreasing thereafter. Spring and autumn cholera, assuming societal conditions remain constant e.g., at the current rate, may decrease. However significant shifts were noted in the magnitude of river discharge suggesting that cholera dynamics of the delta may well demonstrate an uncertain predictable pattern of occurrence over the next century.

Interactive exploration of microstructural features in gigapixel microscopy images - Hsueh-Chien Cheng; Cardone, Antonio; Varshney, Amitabh (IEEE International Conference on Image Processing, 2017)
Modern imaging technologies enable the study of microstructural features, which require capturing the finest details in high-resolution gigapixel images. Nevertheless, the resolution disparity between gigapixel images and megapixel displays presents a challenge to effective visual analysis because subtle texture differences are hardly perceivable at coarser resolutions. In this paper we present a hierarchical segmentation technique based on joint distribution of intensity and noise-resistant local binary patterns to differentiate subtle microstructural textures across various scales. The coarse-to-fine segmentation procedure subdivides each parent segment into texturally-distinct child segments at progressively higher resolutions. The hierarchical structure of segments allows creating intermediate segmentation results interactively. Based on the intermediate results, we highlight regions with texture differences using distinct colors, which provide salient visual hints to users despite of the current viewing resolution. Our new technique has been validated on large microscopy images and shows promising results.
Keywords: gigapixel images; Image segmentation

Vibrio cholerae O1 with Reduced Susceptibility to Ciprofloxacin and Azithromycin Isolated from a Rural Coastal Area of Bangladesh - Rashed, Shah M.; Hasan, Nur A.; Alam, Munirul; Sadique, Abdus; Sultana, Marzia; Hoq, Md. Mozammel; Sack, R. Bradley; Rita R Colwell; Huq, Anwar (Frontiers in Microbiology, 2017)
Cholera outbreaks occur each year in the remote coastal areas of Bangladesh and epidemiological surveillance and routine monitoring of cholera in these areas is challenging. In this study, a total of 97 Vibrio cholerae O1 isolates from Mathbaria, Bangladesh, collected during 2010 and 2014 were analyzed for phenotypic and genotypic traits, including antimicrobial susceptibility. Of the 97 isolates, 95 possessed CTX-phage mediated genes, ctxA, ace, and zot, and two lacked the cholera toxin gene, ctxA. Also both CTX+ and CTX− V. cholerae O1 isolated in this study carried rtxC, tcpAET, and hlyA. The classical cholera toxin gene, ctxB1, was detected in 87 isolates, while eight had ctxB7. Of 95 CTX+ V. cholerae O1, 90 contained rstRET and 5 had rstRCL. All isolates, except two, contained SXT related integrase intSXT. Resistance to penicillin, streptomycin, nalidixic acid, sulfamethoxazole-trimethoprim, erythromycin, and tetracycline varied between the years of study period. Most importantly, 93% of the V. cholerae O1 were multidrug resistant. Six different resistance profiles were observed, with resistance to streptomycin, nalidixic acid, tetracycline, and sulfamethoxazole-trimethoprim predominant every year. Ciprofloxacin and azithromycin MIC were 0.003–0.75 and 0.19–2.00 μg/ml, respectively, indicating reduced susceptibility to these antibiotics. Sixteen of the V. cholerae O1 isolates showed higher MIC for azithromycin (≥0.5 μg/ml) and were further examined for 10 macrolide resistance genes, erm(A), erm(B), erm(C), ere(A), ere(B), mph(A), mph(B), mph(D), mef(A), and msr(A) with none testing positive for the macrolide resistance genes.

Membrane Bioreactor-Based Wastewater Treatment Plant in Saudi Arabia: Reduction of Viral Diversity, Load, and Infectious Capacity - Jumat, Muhammad; Hasan, Nur; Subramanian, Poorani; Heberling, Colin; Rita R Colwell; Hong, Pei-Ying (Water, 2017)

The microbiomes of blowflies and houseflies as bacterial transmission reservoirs - Junqueira, AC; Ratan, Aakrosh; Acerbi, Enzo; Drautz-Moses, Daniela I.; Premkrishnan, BNV; Costea, PI; Linz, Bodo; Purbojati, Rikky W.; Paulo, Daniel F.; Gaultier, Nicolas E.; Subramanian, Poorani; Hasan, Nur A.; et al. (Scientific Reports, 2017)
Blowflies and houseflies are mechanical vectors inhabiting synanthropic environments around the world. They feed and breed in fecal and decaying organic matter, but the microbiome they harbour and transport is largely uncharacterized. We sampled 116 individual houseflies and blowflies from varying habitats on three continents and subjected them to high-coverage, whole-genome shotgun sequencing. This allowed for genomic and metagenomic analyses of the host-associated microbiome at the species level. Both fly host species segregate based on principal coordinate analysis of their microbial communities, but they also show an overlapping core microbiome. Legs and wings displayed the largest microbial diversity and were shown to be an important route for microbial dispersion. The environmental sequencing approach presented here detected a stochastic distribution of human pathogens, such as Helicobacter pylori, thereby demonstrating the potential of flies as proxies for environmental and public health surveillance.

Natural Disasters and Cholera Outbreaks: Current Understanding and Future Outlook - Jutla, Antarpreet; Khan, Rakibul; Rita R Colwell (Current Environmental Health Reports, 2017)
Purpose of Review Diarrheal diseases remain a serious global public health threat, especially for those populations lacking access to safe water and sanitation infrastructure. Although association of several diarrheal diseases, e.g., cholera, shigellosis, etc., with climatic processes has been documented, the global human population remains at heightened risk of outbreak of diseases after natural disasters, such as earthquakes, floods, or droughts. In this review, cholera was selected as a signature diarrheal disease and the role of natural disasters in triggering and transmitting cholera was analyzed. Recent Findings Key observations include identification of an inherent feedback loop that includes societal structure, prevailing climatic processes, and spatio-temporal seasonal variability of natural disasters. Data obtained from satellite-based remote sensing are concluded to have application, although limited, in predicting risks of a cholera outbreak(s). Summary We argue that with the advent of new high spectral and spatial resolution data, earth observation systems should be seamlessly integrated in a decision support mechanism to be mobilize resources when a region suffers a natural disaster. A framework is proposed that can be used to assess the impact of natural disasters with response to outbreak of cholera, providing assessment of short- and long-term influence of climatic processes on disease outbreaks.

SYN-004 (ribaxamase), an oral beta-lactamase, mitigates antibiotic-mediated dysbiosis in a porcine gut microbiome model - Connelly, S.; Bristol, J.A.; Hubert, S.; Subramanian, P.; Hasan, N.A.; Rita R Colwell; Kaleko, M. (Journal of Applied Microbiology, 2017)
Aim To evaluate an antibiotic inactivation strategy to protect the gut microbiome from antibiotic‐mediated damage. Methods and Results SYN‐004 (ribaxamase) is an orally delivered beta‐lactamase intended to degrade penicillins and cephalosporins within the gastrointestinal tract to protect the microbiome. Pigs (20 kg, n = 10) were treated with ceftriaxone (CRO) (IV, 50 mg kg−1, SID) for 7 days and a cohort (n = 5) received ribaxamase (PO, 75 mg, QID) for 9 days beginning the day before antibiotic administration. Ceftriaxone serum levels were not statistically different in the antibiotic‐alone and antibiotic + ribaxamase groups, indicating ribaxamase did not alter systemic antibiotic levels. Whole‐genome metagenomic analyses of pig faecal DNA revealed that CRO caused significant changes to the gut microbiome and an increased frequency of antibiotic resistance genes. With ribaxamase, the gut microbiomes were not significantly different from pretreatment and antibiotic resistance gene frequency was not increased. Conclusion Ribaxamase mitigated CRO‐mediated gut microbiome dysbiosis and attenuated propagation of the antibiotic resistance genes in pigs. Significance and Impact of the Study Damage of the microbiome can lead to overgrowth of pathogenic organisms and antibiotic exposure can promote selection for antibiotic‐resistant micro‐organisms. Ribaxamase has the potential to become the first therapy designed to protect the gut microbiome from antibiotic‐mediated dysbiosis and reduce emergence of antibiotic resistance.

3D Cellular Morphotyping of Scaffold Niches - Florczyk, Stephen J; Simon, Mylene; Juba, Derek; Pine, P Scott; Sarkar, Sumona; Chen, Desu; Baker, Paula J; Bodhak, Subhadip; Cardone, Antonio; Brady, Mary; others (2016 32nd Southern Biomedical Engineering Conference (SBEC), 2016)

Are natural reservoirs important for cholera surveillance? The case of an outbreak in a Brazilian estuary - Martinelli Filho, J.E.; Lopes, R.M.; Rivera, I.N.G.; Rita R Colwell (Letters in Applied Microbiology, 2016)
Paranaguá Bay is one of the largest estuarine systems on the Southern Brazilian coast. The only recorded cholera outbreak in this region since the early 20th century occurred in 1999 and resulted in 467 cases and at least three reported deaths in a population of approx. 150 000 people. This short communication reports historical, unpublished data related to that outbreak. Water, zooplankton and bivalve samples were collected and evaluated using direct fluorescence assay to determine whether Vibrio cholerae serogroups O1 and O139 were present in the estuarine system at that time. Most of the water (83%) and zooplankton samples (75%) were positive for V. cholerae O1, while V. cholerae O139 was not detected. Shellfish (Mytella sp.) were also positive for V. cholerae O1. These results indicate that the estuary, including biological vectors such as copepods and bivalves, comprise an important reservoir of V. cholerae O1 and a probable waterborne pathway for the disease, in addition to contamination with untreated sewage.

Chitin promotes Mycobacterium ulcerans growth - Sanhueza, Daniel; Chevillon, Christine; Rita R Colwell; Babonneau, Jérémie; Marion, Estelle; Marsollier, Laurent; égan, çois (FEMS Microbiology Ecology, 2016)
Mycobacterium ulcerans (MU) is the causative agent of Buruli ulcer, an emerging human infectious disease. However, both the ecology and life cycle of MU are poorly understood. The occurrence of MU has been linked to the aquatic environment, notably water bodies affected by human activities. It has been hypothesized that one or a combination of environmental factor(s) connected to human activities could favour growth of MU in aquatic systems. Here, we tested in vitro the growth effect of two ubiquitous polysaccharides and five chemical components on MU at concentration ranges shown to occur in endemic regions. Real-time PCR showed that chitin increased MU growth significantly providing a nutrient source or environmental support for the bacillus, thereby, providing a focus on the association between MU and aquatic arthropods. Aquatic environments with elevated population of arthropods provide increased chitin availability and, thereby, enhanced multiplication of MU. If calcium very slightly enhanced MU growth, iron, zinc, sulphate and phosphate did not stimulate MU growth, and at the concentration ranges of this study would limit MU population in natural ecosystems.

Climate influence on Vibrio and associated human diseases during the past half-century in the coastal North Atlantic - Vezzulli, Luigi; Grande, Chiara; Reid, Philip C.; élaouët, Pierre; Edwards, Martin; öfle, Manfred G.; Brettar, Ingrid; Rita R Colwell; Pruzzo, Carla (Proceedings of the National Academy of Sciences, 2016)
Climate change is having a dramatic impact on marine animal and plant communities but little is known of its influence on marine prokaryotes, which represent the largest living biomass in the world oceans and play a fundamental role in maintaining life on our planet. In this study, for the first time to our knowledge, experimental evidence is provided on the link between multidecadal climatic variability in the temperate North Atlantic and the presence and spread of an important group of marine prokaryotes, the vibrios, which are responsible for several infections in both humans and animals. Using archived formalin-preserved plankton samples collected by the Continuous Plankton Recorder survey over the past half-century (1958–2011), we assessed retrospectively the relative abundance of vibrios, including human pathogens, in nine areas of the North Atlantic and North Sea and showed correlation with climate and plankton changes. Generalized additive models revealed that long-term increase in Vibrio abundance is promoted by increasing sea surface temperatures (up to ∼1.5 °C over the past 54 y) and is positively correlated with the Northern Hemisphere Temperature (NHT) and Atlantic Multidecadal Oscillation (AMO) climatic indices (P < 0.001). Such increases are associated with an unprecedented occurrence of environmentally acquired Vibrio infections in the human population of Northern Europe and the Atlantic coast of the United States in recent years.

Comparison of inferred relatedness based on multilocus variable-number tandem-repeat analysis and whole genome sequencing of Vibrio cholerae O1 - Rashid, Mahamud-ur; Almeida, Mathieu; Azman, Andrew S.; Lindsay, Brianna R.; Sack, David A.; Rita R Colwell; Huq, Anwar; Morris, J. Glenn; Alam, Munirul; Stine, O. Colin (FEMS Microbiology Letters, 2016)
Vibrio cholerae causes cholera, a severe diarrheal disease. Understanding the local genetic diversity and transmission of V. cholerae will improve our ability to control cholera. Vibrio cholerae isolates clustered in genetically related groups (clonal complexes, CC) by multilocus variable tandem-repeat analysis (MLVA) were compared by whole genome sequencing (WGS). Isolates in CC1 had been isolated from two geographical locations. Isolates in a second genetically distinct group, CC2, were isolated only at one location. Using WGS, CC1 isolates from both locations revealed, on average, 43.8 nucleotide differences, while those strains comprising CC2 averaged 19.7 differences. Strains from both MLVA-CCs had an average difference of 106.6. Thus, isolates comprising CC1 were more closely related (P < 10−6) to each other than to isolates in CC2. Within a MLVA-CC, after removing all paralogs, alternative alleles were found in all possible combinations on separate chromosomes indicative of recombination within the core genome. Including recombination did not affect the distinctiveness of the MLVA-CCs when measured by WGS. We found that WGS generally reflected the same genetic relatedness of isolates as MLVA, indicating that isolates from the same MLVA-CC shared a more recent common ancestor than isolates from the same location that clustered in a distinct MLVA-CC.

Computational study of the inhibitory mechanism of the kinase CDK5 hyperactivity by peptide p5 and derivation of a pharmacophore - Cardone, Antonio; Brady, M.; Sriram, R.; Pant, H. C.; Hassan, S. A. (Journal of Computer-Aided Molecular Design, 2016)

Cross-talk among flesh-eating Aeromonas hydrophila strains in mixed infection leading to necrotizing fasciitis - Ponnusamy, Duraisamy; Kozlova, Elena V.; Sha, Jian; Erova, Tatiana E.; Azar, Sasha R.; Fitts, Eric C.; Kirtley, Michelle L.; Tiner, Bethany L.; Andersson, Jourdan A.; Grim, Christopher J.; Isom, Richard P.; Hasan, Nur A.; et al. (Proceedings of the National Academy of Sciences, 2016)
Necrotizing fasciitis (NF) caused by flesh-eating bacteria is associated with high case fatality. In an earlier study, we reported infection of an immunocompetent individual with multiple strains of Aeromonas hydrophila (NF1–NF4), the latter three constituted a clonal group whereas NF1 was phylogenetically distinct. To understand the complex interactions of these strains in NF pathophysiology, a mouse model was used, whereby either single or mixed A. hydrophila strains were injected intramuscularly. NF2, which harbors exotoxin A (exoA) gene, was highly virulent when injected alone, but its virulence was attenuated in the presence of NF1 (exoA-minus). NF1 alone, although not lethal to animals, became highly virulent when combined with NF2, its virulence augmented by cis-exoA expression when injected alone in mice. Based on metagenomics and microbiological analyses, it was found that, in mixed infection, NF1 selectively disseminated to mouse peripheral organs, whereas the other strains (NF2, NF3, and NF4) were confined to the injection site and eventually cleared. In vitro studies showed NF2 to be more effectively phagocytized and killed by macrophages than NF1. NF1 inhibited growth of NF2 on solid media, but ExoA of NF2 augmented virulence of NF1 and the presence of NF1 facilitated clearance of NF2 from animals either by enhanced priming of host immune system or direct killing via a contact-dependent mechanism.

Enrichment dynamics of Listeria monocytogenes and the associated microbiome from naturally contaminated ice cream linked to a listeriosis outbreak - Ottesen, Andrea; Ramachandran, Padmini; Reed, Elizabeth; White, James R.; Hasan, Nur; Subramanian, Poorani; Ryan, Gina; Jarvis, Karen; Grim, Christopher; Daquiqan, Ninalynn; Hanes, Darcy; Allard, Marc; et al. (BMC Microbiology, 2016)

In Plain View: A Transparent Systems Approach for Enhancing Health Policy Decisions - Guru Madhavan; Charles E. Phelps; Rita R Colwell; Rino Rappuoli; Harvey V. Fineberg (The Bridge, 2016)

IncA/C Conjugative Plasmids Mobilize a New Family of Multidrug Resistance Islands in Clinical Vibrio cholerae Non-O1/Non-O139 Isolates from Haiti - Carraro, Nicolas; Rivard, Nicolas; Ceccarelli, Daniela; Rita R Colwell; Burrus, Vincent (mBio, 2016)
Mobile genetic elements play a pivotal role in the adaptation of bacterial populations, allowing them to rapidly cope with hostile conditions, including the presence of antimicrobial compounds. IncA/C conjugative plasmids (ACPs) are efficient vehicles for dissemination of multidrug resistance genes in a broad range of pathogenic species of Enterobacteriaceae. ACPs have sporadically been reported in Vibrio cholerae, the infectious agent of the diarrheal disease cholera. The regulatory network that controls ACP mobility ultimately depends on the transcriptional activation of multiple ACP-borne operons by the master activator AcaCD. Beyond ACP conjugation, AcaCD has also recently been shown to activate the expression of genes located in the Salmonella genomic island 1 (SGI1). Here, we describe MGIVchHai6, a novel and unrelated mobilizable genomic island (MGI) integrated into the 3′ end of trmE in chromosome I of V. cholerae HC-36A1, a non-O1/non-O139 multidrug-resistant clinical isolate recovered from Haiti in 2010. MGIVchHai6 contains a mercury resistance transposon and an integron In104-like multidrug resistance element similar to the one of SGI1. We show that MGIVchHai6 excises from the chromosome in an AcaCD-dependent manner and is mobilized by ACPs. Acquisition of MGIVchHai6 confers resistance to β-lactams, sulfamethoxazole, tetracycline, chloramphenicol, trimethoprim, and streptomycin/spectinomycin. In silico analyses revealed that MGIVchHai6-like elements are carried by several environmental and clinical V. cholerae strains recovered from the Indian subcontinent, as well as from North and South America, including all non-O1/non-O139 clinical isolates from Haiti.

Modeling Sustainability: Population, Inequality, Consumption, and Bidirectional Coupling of the Earth and Human Systems - Motesharrei, Safa; Rivas, Jorge; Kalnay, Eugenia; Asrar, Ghassem R.; Busalacchi, Antonio J.; Cahalan, Robert F.; Cane, Mark A.; Rita R Colwell; Feng, Kuishuang; Franklin, Rachel S.; Hubacek, Klaus; Miralles-Wilhelm, Fernando; et al. (National Science Review, 2016)
Over the last two centuries, the impact of the Human System has grown dramatically, becoming strongly dominant within the Earth System in many different ways. Consumption, inequality, and population have increased extremely fast, especially since about 1950, threatening to overwhelm the many critical functions and ecosystems of the Earth System. Changes in the Earth System, in turn, have important feedback effects on the Human System, with costly and potentially serious consequences. However, current models do not incorporate these critical feedbacks. We argue that in order to understand the dynamics of either system, Earth System Models must be coupled with Human System Models through bidirectional couplings representing the positive, negative, and delayed feedbacks that exist in the real systems. In particular, key Human System variables, such as demographics, inequality, economic growth, and migration, are not coupled with the Earth System but are instead driven by exogenous estimates, such as United Nations population projections. This makes current models likely to miss important feedbacks in the real Earth–Human system, especially those that may result in unexpected or counterintuitive outcomes, and thus requiring different policy interventions from current models. The importance and imminence of sustainability challenges, the dominant role of the Human System in the Earth System, and the essential roles the Earth System plays for the Human System, all call for collaboration of natural scientists, social scientists, and engineers in multidisciplinary research and modeling to develop coupled Earth–Human system models for devising effective science-based policies and measures to benefit current and future generations.

Phylogenetic Diversity of Vibrio cholerae Associated with Endemic Cholera in Mexico from 1991 to 2008 - Choi, Seon Y; Rashed, Shah M.; Hasan, Nur A.; Alam, Munirul; Islam, Tarequl; Sadique, Abdus; Johura, Fatema-Tuz; Eppinger, Mark; Ravel, Jacques; Huq, Anwar; Cravioto, Alejandro; Rita R Colwell (mBio, 2016)
An outbreak of cholera occurred in 1991 in Mexico, where it had not been reported for more than a century and is now endemic. Vibrio cholerae O1 prototype El Tor and classical strains coexist with altered El Tor strains (1991 to 1997). Nontoxigenic (CTX−) V. cholerae El Tor dominated toxigenic (CTX+) strains (2001 to 2003), but V. cholerae CTX+ variant El Tor was isolated during 2004 to 2008, outcompeting CTX− V. cholerae. Genomes of six Mexican V. cholerae O1 strains isolated during 1991 to 2008 were sequenced and compared with both contemporary and archived strains of V. cholerae. Three were CTX+ El Tor, two were CTX− El Tor, and the remaining strain was a CTX+ classical isolate. Whole-genome sequence analysis showed the six isolates belonged to five distinct phylogenetic clades. One CTX− isolate is ancestral to the 6th and 7th pandemic CTX+ V. cholerae isolates. The other CTX− isolate joined with CTX− non-O1/O139 isolates from Haiti and seroconverted O1 isolates from Brazil and Amazonia. One CTX+ isolate was phylogenetically placed with the sixth pandemic classical clade and the V. cholerae O395 classical reference strain. Two CTX+ El Tor isolates possessing intact Vibrio seventh pandemic island II (VSP-II) are related to hybrid El Tor isolates from Mozambique and Bangladesh. The third CTX+ El Tor isolate contained West African-South American (WASA) recombination in VSP-II and showed relatedness to isolates from Peru and Brazil. Except for one isolate, all Mexican isolates lack SXT/R391 integrative conjugative elements (ICEs) and sensitivity to selected antibiotics, with one isolate resistant to streptomycin. No isolates were related to contemporary isolates from Asia, Africa, or Haiti, indicating phylogenetic diversity.

Recognition of achievement – priorities and process - Madsen, Lynnette D.; Rita R Colwell (Materials Today, 2016)

Reduced Susceptibility to Extended-Spectrum β-Lactams in Vibrio cholerae Isolated in Bangladesh - Ceccarelli, Daniela; Alam, Munirul; Huq, Anwar; Rita R Colwell (Frontiers in Public Health, 2016)

Strategic Planning in Population Health and Public Health Practice: A Call to Action for Higher Education - Phelps, Charles; Madhavan, Guruprasad; Rappuoli, Rino; LEVIN, SCOTT; Shortlife, Edward; Rita R Colwell (The Milbank Quarterly, 2016)
POLICY POINTS: Scarce resources, especially in population health and public health practice, underlie the importance of strategic planning. Public health agencies' current planning and priority setting efforts are often narrow, at times opaque, and focused on single metrics such as cost-effectiveness. As demonstrated by SMART Vaccines, a decision support software system developed by the Institute of Medicine and the National Academy of Engineering, new approaches to strategic planning allow the formal incorporation of multiple stakeholder views and multicriteria decision making that surpass even those sophisticated cost-effectiveness analyses widely recommended and used for public health planning. Institutions of higher education can and should respond by building on modern strategic planning tools as they teach their students how to improve population health and public health practice. CONTEXT: Strategic planning in population health and public health practice often uses single indicators of success or, when using multiple indicators, provides no mechanism for coherently combining the assessments. Cost-effectiveness analysis, the most complex strategic planning tool commonly applied in public health, uses only a single metric to evaluate programmatic choices, even though other factors often influence actual decisions. METHODS: Our work employed a multicriteria systems analysis approach--specifically, multiattribute utility theory--to assist in strategic planning and priority setting in a particular area of health care (vaccines), thereby moving beyond the traditional cost-effectiveness analysis approach. FINDINGS: (1) Multicriteria systems analysis provides more flexibility, transparency, and clarity in decision support for public health issues compared with cost-effectiveness analysis. (2) More sophisticated systems-level analyses will become increasingly important to public health as disease burdens increase and the resources to deal with them become scarcer. CONCLUSIONS: The teaching of strategic planning in public health must be expanded in order to fill a void in the profession's planning capabilities. Public health training should actively incorporate model building, promote the interactive use of software tools, and explore planning approaches that transcend restrictive assumptions of cost-effectiveness analysis. The Strategic Multi-Attribute Ranking Tool for Vaccines (SMART Vaccines), which was recently developed by the Institute of Medicine and the National Academy of Engineering to help prioritize new vaccine development, is a working example of systems analysis as a basis for decision support.

Building Infectious Disease Research Programs to Promote Security and Enhance Collaborations with Countries of the Former Soviet Union - Bartholomew, James C.; Pearson, Andrew D.; Stenseth, Nils C.; LeDuc, James W.; Hirschberg, David L.; Rita R Colwell (Frontiers in Public Health, 2015)

Concordance and discordance of sequence survey methods for molecular epidemiology - Castro-Nallar, Eduardo; Hasan, Nur A.; Cebula, Thomas A.; Rita R Colwell; Robison, Richard A.; Johnson, W. Evan; Crandall, Keith A. (PeerJ, 2015)
The post-genomic era is characterized by the direct acquisition and analysis of genomic data with many applications, including the enhancement of the understanding of microbial epidemiology and pathology. However, there are a number of molecular approaches to survey pathogen diversity, and the impact of these different approaches on parameter estimation and inference are not entirely clear. We sequenced whole genomes of bacterial pathogens, Burkholderia pseudomallei, Yersinia pestis, and Brucella spp. (60 new genomes), and combined them with 55 genomes from GenBank to address how different molecular survey approaches (whole genomes, SNPs, and MLST) impact downstream inferences on molecular evolutionary parameters, evolutionary relationships, and trait character associations. We selected isolates for sequencing to represent temporal, geographic origin, and host range variability. We found that substitution rate estimates vary widely among approaches, and that SNP and genomic datasets yielded different but strongly supported phylogenies. MLST yielded poorly supported phylogenies, especially in our low diversity dataset, i.e., Y. pestis. Trait associations showed that B. pseudomallei and Y. pestis phylogenies are significantly associated with geography, irrespective of the molecular survey approach used, while Brucella spp. phylogeny appears to be strongly associated with geography and host origin. We contrast inferences made among monomorphic (clonal) and non-monomorphic bacteria, and between intra- and inter-specific datasets. We also discuss our results in light of underlying assumptions of different approaches.

Deep-sea hydrothermal vent bacteria related to human pathogenic Vibrio species - Hasan, Nur A.; Grim, Christopher J.; Lipp, Erin K.; Rivera, Irma N. G.; Chun, Jongsik; Haley, Bradd J.; Taviani, Elisa; Choi, Seon Young; Hoq, Mozammel; Munk, A. Christine; Brettin, Thomas S.; Bruce, David; et al. (Proceedings of the National Academy of Sciences, 2015)
Vibrio species are both ubiquitous and abundant in marine coastal waters, estuaries, ocean sediment, and aquaculture settings worldwide. We report here the isolation, characterization, and genome sequence of a novel Vibrio species, Vibrio antiquarius, isolated from a mesophilic bacterial community associated with hydrothermal vents located along the East Pacific Rise, near the southwest coast of Mexico. Genomic and phenotypic analysis revealed V. antiquarius is closely related to pathogenic Vibrio species, namely Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio harveyi, and Vibrio vulnificus, but sufficiently divergent to warrant a separate species status. The V. antiquarius genome encodes genes and operons with ecological functions relevant to the environment conditions of the deep sea and also harbors factors known to be involved in human disease caused by freshwater, coastal, and brackish water vibrios. The presence of virulence factors in this deep-sea Vibrio species suggests a far more fundamental role of these factors for their bacterial host. Comparative genomics revealed a variety of genomic events that may have provided an important driving force in V. antiquarius evolution, facilitating response to environmental conditions of the deep sea.

Detection and characterization of nonspecific, sparsely populated binding modes in the early stages of complexation. - Cardone, Antonio; Bornstein, Aaron; Pant, Harish C; Brady, Mary; Sriram, Ram; Hassan, Sergio A (J Comput Chem, 2015)
A method is proposed to study protein-ligand binding in a system governed by specific and nonspecific interactions. Strong associations lead to narrow distributions in the proteins configuration space; weak and ultraweak associations lead instead to broader distributions, a manifestation of nonspecific, sparsely populated binding modes with multiple interfaces. The method is based on the notion that a discrete set of preferential first-encounter modes are metastable states from which stable (prerelaxation) complexes at equilibrium evolve. The method can be used to explore alternative pathways of complexation with statistical significance and can be integrated into a general algorithm to study protein interaction networks. The method is applied to a peptide-protein complex. The peptide adopts several low-population conformers and binds in a variety of modes with a broad range of affinities. The system is thus well suited to analyze general features of binding, including conformational selection, multiplicity of binding modes, and nonspecific interactions, and to illustrate how the method can be applied to study these problems systematically. The equilibrium distributions can be used to generate biasing functions for simulations of multiprotein systems from which bulk thermodynamic quantities can be calculated. © 2015 Wiley Periodicals, Inc.

Diagnostic Approach for Monitoring Hydroclimatic Conditions Related to Emergence of West Nile Virus in West Virginia - Jutla, Antarpreet; Huq, Anwar; Rita R Colwell (Frontiers in Public Health, 2015)
West Nile virus (WNV), mosquito-borne and water-based disease, is increasingly a global threat to public health. Since its appearance in the northeastern United States in 1999, WNV has since been reported in several states in the continental United States. The objective of this study is to highlight role of hydroclimatic processes estimated through satellite sensors in capturing conditions for emergence of the vectors in historically disease free regions. We tested the hypothesis that an increase in surface temperature, in combination with intensification of vegetation, and enhanced precipitation, lead to conditions favorable for vector (mosquito) growth. Analysis of land surface temperature (LST) pattern shows that temperature values >16°C, with heavy precipitation, may lead to abundance of the mosquito population. This hypothesis was tested in West Virginia where a sudden epidemic of WNV infection was reported in 2012. Our results emphasize the value of hydroclimatic processes estimated by satellite remote sensing, as well as continued environmental surveillance of mosquitoes, because when a vector-borne infection like WNV is discovered in contiguous regions, the risk of spread of WNV mosquitoes increase at points where appropriate hydroclimatic processes intersect with the vector niche.

Downscaling river discharge to assess the effects of climate change on cholera outbreaks in the Bengal Delta - Nasr-Azadani, F; Unnikrishnan, A; Akanda, A; Islam, S; Alam, M; Huq, A; Jutla, A; Rita R Colwell (Climate Research, 2015)
Endemic cholera in the Bengal Delta region of South Asia has been associated with asymmetric and episodic variability of river discharge. Spring cholera was found to be related to intrusion of bacteria-laden coastal seawater during low flow seasons. Autumn cholera was hypothesized to result from cross-contamination of water resources when high river discharge causes massive inland inundation. The effect of climate change on diarrheal diseases has not been explored, because of the difficulties in establishing linkages between coarse-resolution global climate model outputs with localized disease outbreaks. Since rivers act as corridors for transport of cholera bacteria, the first step is to understand the discharge variability that may occur with climate change and whether it is linked to cholera. Here, we present a framework for downscaling precipitation from global climate models for river discharge in the Ganges-Brahmaputra-Meghna basin. Using a data-mining method that includes particle swarm optimization-based support vector regression, precipitation was downscaled for a statistical multiple regressive model to estimate river discharge in the basin. Key results from an ensemble of HadCM3, GFDL, and ECHAM5 models indicated 8 and 7.5% increase in flows for the IPCC A1B and A2 scenarios, respectively. The majority of the changes are attributable to increases in flows from February through August for both scenarios, with little to no change in seasonality of high and low flows during the next century. The probability of spring and autumn cholera is likely to increase steadily in the endemic region of the Bengal Delta.

Environmental Surveillance for Toxigenic Vibrio cholerae in Surface Waters of Haiti - Hill, Vincent R.; Humphrys, Michael S.; Kahler, Amy M.; Boncy, Jacques; Tarr, Cheryl L.; Huq, Anwar; Chen, Arlene; Katz, Lee S.; Mull, Bonnie J.; Derado, Gordana; Haley, Bradd J.; Freeman, Nicole; et al. (The American Journal of Tropical Medicine and Hygiene, 2015)
Epidemic cholera was reported in Haiti in 2010, with no information available on the occurrence or geographic distribution of toxigenic Vibrio cholerae in Haitian waters. In a series of field visits conducted in Haiti between 2011 and 2013, water and plankton samples were collected at 19 sites. Vibrio cholerae was detected using culture, polymerase chain reaction, and direct viable count methods (DFA-DVC). Cholera toxin genes were detected by polymerase chain reaction in broth enrichments of samples collected in all visits except March 2012. Toxigenic V. cholerae was isolated from river water in 2011 and 2013. Whole genome sequencing revealed that these isolates were a match to the outbreak strain. The DFA-DVC tests were positive for V. cholerae O1 in plankton samples collected from multiple sites. Results of this survey show that toxigenic V. cholerae could be recovered from surface waters in Haiti more than 2 years after the onset of the epidemic.

Estimating Actin Fiber Orientation using Interpolation-Based Grey-Level Co-Occurrence Matrix Computation - Cardone, Antonio; Brady, Mary; Kociolek, Marcin; Bajcsy, Peter (BioImage Informatics Conference, 2015)

Hybrid Vibrio cholerae El Tor Lacking SXT Identified as the Cause of a Cholera Outbreak in the Philippines - Klinzing, David C.; Choi, Seon Young; Hasan, Nur A.; Matias, Ronald R.; Tayag, Enrique; Geronimo, Josefina; Skowronski, Evan; Rashed, Shah M.; Kawashima, Kent; Rosenzweig, C. Nicole; Gibbons, Henry S.; Torres, Brian C.; et al. (mBio, 2015)
Cholera continues to be a global threat, with high rates of morbidity and mortality. In 2011, a cholera outbreak occurred in Palawan, Philippines, affecting more than 500 people, and 20 individuals died. Vibrio cholerae O1 was confirmed as the etiological agent. Source attribution is critical in cholera outbreaks for proper management of the disease, as well as to control spread. In this study, three V. cholerae O1 isolates from a Philippines cholera outbreak were sequenced and their genomes analyzed to determine phylogenetic relatedness to V. cholerae O1 isolates from recent outbreaks of cholera elsewhere. The Philippines V. cholerae O1 isolates were determined to be V. cholerae O1 hybrid El Tor belonging to the seventh-pandemic clade. They clustered tightly, forming a monophyletic clade closely related to V. cholerae O1 hybrid El Tor from Asia and Africa. The isolates possess a unique multilocus variable-number tandem repeat analysis (MLVA) genotype (12-7-9-18-25 and 12-7-10-14-21) and lack SXT. In addition, they possess a novel 15-kb genomic island (GI-119) containing a predicted type I restriction-modification system. The CTXΦ-RS1 array of the Philippines isolates was similar to that of V. cholerae O1 MG116926, a hybrid El Tor strain isolated in Bangladesh in 1991. Overall, the data indicate that the Philippines V. cholerae O1 isolates are unique, differing from recent V. cholerae O1 isolates from Asia, Africa, and Haiti. Furthermore, the results of this study support the hypothesis that the Philippines isolates of V. cholerae O1 are indigenous and exist locally in the aquatic ecosystem of the Philippines.

Molecular tools in understanding the evolution of Vibrio cholerae - Rahaman, Md. Habibur; Islam, Tarequl; Rita R Colwell; Alam, Munirul (Frontiers in Microbiology, 2015)
Vibrio cholerae, the etiological agent of cholera, has been a scourge for centuries. Cholera remains a serious health threat for developing countries and has been responsible for millions of deaths globally over the past 200 years. Identification of V. cholerae has been accomplished using a variety of methods, ranging from phenotypic strategies to DNA based molecular typing and currently whole genomic approaches. This array of methods has been adopted in epidemiological investigations, either singly or in the aggregate, and more recently for evolutionary analyses of V. cholerae. Because the new technologies have been developed at an ever increasing pace, this review of the range of fingerprinting strategies, their relative advantages and limitations, and cholera case studies was undertaken. The task was challenging, considering the vast amount of the information available. To assist the study, key references representative of several areas of research are provided with the intent to provide readers with a comprehensive view of recent advances in the molecular epidemiology of V. cholerae. Suggestions for ways to obviate many of the current limitations of typing techniques are also provided. In summary, a comparative report has been prepared that includes the range from traditional typing to whole genomic strategies.

Non-O1/Non-O139 Vibrio cholerae Carrying Multiple Virulence Factors and V. cholerae O1 in the Chesapeake Bay, Maryland - Ceccarelli, Daniela; Chen, Arlene; Hasan, Nur A.; Rashed, Shah M.; Huq, Anwar; Rita R Colwell (Applied and Environmental Microbiology, 2015)
Non-O1/non-O139 Vibrio cholerae inhabits estuarine and coastal waters globally, but its clinical significance has not been sufficiently investigated, despite the fact that it has been associated with septicemia and gastroenteritis. The emergence of virulent non-O1/non-O139 V. cholerae is consistent with the recognition of new pathogenic variants worldwide. Oyster, sediment, and water samples were collected during a vibrio surveillance program carried out from 2009 to 2012 in the Chesapeake Bay, Maryland. V. cholerae O1 was detected by a direct fluorescent-antibody (DFA) assay but was not successfully cultured, whereas 395 isolates of non-O1/non-O139 V. cholerae were confirmed by multiplex PCR and serology. Only a few of the non-O1/non-O139 V. cholerae isolates were resistant to ampicillin and/or penicillin. Most of the isolates were sensitive to all antibiotics tested, and 77 to 90% carried the El Tor variant hemolysin gene hlyA ET, the actin cross-linking repeats in toxin gene rtxA, the hemagglutinin protease gene hap, and the type 6 secretion system. About 19 to 21% of the isolates carried the neuraminidase-encoding gene nanH and/or the heat-stable toxin (NAG-ST), and only 5% contained a type 3 secretion system. None of the non-O1/non-O139 V. cholerae isolates contained Vibrio pathogenicity island-associated genes. However, ctxA, ace, or zot was present in nine isolates. Fifty-five different genotypes showed up to 12 virulence factors, independent of the source of isolation, and represent the first report of both antibiotic susceptibility and virulence associated with non-O1/non-O139 V. cholerae from the Chesapeake Bay. Since these results confirm the presence of potentially pathogenic non-O1/non-O139 V. cholerae, monitoring for total V. cholerae, regardless of serotype, should be done within the context of public health.

Nontoxigenic Vibrio cholerae Non-O1/O139 Isolate from a Case of Human Gastroenteritis in the U.S. Gulf Coast - Hasan, Nur A.; Rezayat, Talayeh; Blatz, Peter J.; Choi, Seon Young; Griffitt, Kimberly J.; Rashed, Shah M.; Huq, Anwar; Conger, Nicholas G.; Rita R Colwell; Grimes, D. Jay (Journal of Clinical Microbiology, 2015)
An occurrence of Vibrio cholerae non-O1/O139 gastroenteritis in the U.S. Gulf Coast is reported here. Genomic analysis revealed that the isolate lacked known virulence factors associated with the clinical outcome of a V. cholerae infection but did contain putative genomic islands and other accessory virulence factors. Many of these factors are widespread among environmental strains of V. cholerae, suggesting that there might be additional virulence factors in non-O1/O139 V. cholerae yet to be determined. Phylogenetic analysis revealed that the isolate belonged to a phyletic lineage of environmental V. cholerae isolates associated with sporadic cases of gastroenteritis in the Western Hemisphere, suggesting a need to monitor non-O1/O139 V. cholerae in the interest of public health.

Occurrence and Diversity of Clinically Important Vibrio Species in the Aquatic Environment of Georgia - Kokashvili, Tamar; Whitehouse, Chris A.; Tskhvediani, Ana; Grim, Christopher J.; Elbakidze, Tinatin; Mitaishvili, Nino; Janelidze, Nino; Jaiani, Ekaterine; Haley, Bradd J.; Lashkhi, Nino; Huq, Anwar; Rita R Colwell; et al. (Frontiers in Public Health, 2015)

Predictive Time Series Analysis Linking Bengal Cholera with Terrestrial Water Storage Measured from Gravity Recovery and Climate Experiment Sensors - Rita R Colwell; Unnikrishnan, Avinash; Jutla, Antarpreet; Huq, Anwar; Akanda, Ali (The American Journal of Tropical Medicine and Hygiene, 2015)
Outbreaks of diarrheal diseases, including cholera, are related to floods and droughts in regions where water and sanitation infrastructure are inadequate or insufficient. However, availability of data on water scarcity and abundance in transnational basins, are a prerequisite for developing cholera forecasting systems. With more than a decade of terrestrial water storage (TWS) data from the Gravity Recovery and Climate Experiment, conditions favorable for predicting cholera occurrence may now be determined. We explored lead–lag relationships between TWS in the Ganges–Brahmaputra–Meghna basin and endemic cholera in Bangladesh. Since bimodal seasonal peaks in cholera in Bangladesh occur during spring and autumn seasons, two separate logistical models between TWS and disease time series (2002–2010) were developed. TWS representing water availability showed an asymmetrical, strong association with cholera prevalence in the spring (τ = −0.53; P < 0.001) and autumn (τ = 0.45; P < 0.001) up to 6 months in advance. One unit (centimeter of water) decrease in water availability in the basin increased odds of above normal cholera by 24% (confidence interval [CI] = 20–31%; P < 0.05) in the spring, while an increase in regional water by 1 unit, through floods, increased odds of above average cholera in the autumn by 29% (CI = 22–33%; P < 0.05).

Rapid Proliferation of Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae during Freshwater Flash Floods in French Mediterranean Coastal Lagoons - Esteves, Kevin; Hervio-Heath, Dominique; Mosser, Thomas; Rodier, Claire; Tournoud, Marie-George; Jumas-Bilak, Estelle; Rita R Colwell; Monfort, Patrick (Applied and Environmental Microbiology, 2015)
Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae of the non-O1/non-O139 serotype are present in coastal lagoons of southern France. In these Mediterranean regions, the rivers have long low-flow periods followed by short-duration or flash floods during and after heavy intense rainstorms, particularly at the end of the summer and in autumn. These floods bring large volumes of freshwater into the lagoons, reducing their salinity. Water temperatures recorded during sampling (15 to 24°C) were favorable for the presence and multiplication of vibrios. In autumn 2011, before heavy rainfalls and flash floods, salinities ranged from 31.4 to 36.1‰ and concentrations of V. parahaemolyticus, V. vulnificus, and V. cholerae varied from 0 to 1.5 × 103 most probable number (MPN)/liter, 0.7 to 2.1 × 103 MPN/liter, and 0 to 93 MPN/liter, respectively. Following heavy rainstorms that generated severe flash flooding and heavy discharge of freshwater, salinity decreased, reaching 2.2 to 16.4‰ within 15 days, depending on the site, with a concomitant increase in Vibrio concentration to ca. 104 MPN/liter. The highest concentrations were reached with salinities between 10 and 20‰ for V. parahaemolyticus, 10 and 15‰ for V. vulnificus, and 5 and 12‰ for V. cholerae. Thus, an abrupt decrease in salinity caused by heavy rainfall and major flooding favored growth of human-pathogenic Vibrio spp. and their proliferation in the Languedocian lagoons. Based on these results, it is recommended that temperature and salinity monitoring be done to predict the presence of these Vibrio spp. in shellfish-harvesting areas of the lagoons.

Satellite Based Assessment of Hydroclimatic Conditions Related to Cholera in Zimbabwe - Jutla, Antarpreet; Aldaach, Haidar; Billian, Hannah; Akanda, Ali; Huq, Anwar; Rita R Colwell (PLOS ONE, 2015)
Introduction Cholera, an infectious diarrheal disease, has been shown to be associated with large scale hydroclimatic processes. The sudden and sporadic occurrence of epidemic cholera is linked with high mortality rates, in part, due to uncertainty in timing and location of outbreaks. Improved understanding of the relationship between pathogenic abundance and climatic processes allows prediction of disease outbreak to be an achievable goal. In this study, we show association of large scale hydroclimatic processes with the cholera epidemic in Zimbabwe reported to have begun in Chitungwiza, a city in Mashonaland East province, in August, 2008. Principal Findings Climatic factors in the region were found to be associated with triggering cholera outbreak and are shown to be related to anomalies of temperature and precipitation, validating the hypothesis that poor conditions of sanitation, coupled with elevated temperatures, and followed by heavy rainfall can initiate outbreaks of cholera. Spatial estimation by satellite of precipitation and global gridded air temperature captured sensitivities in hydroclimatic conditions that permitted identification of the location in the region where the disease outbreak began. Discussion Satellite derived hydroclimatic processes can be used to capture environmental conditions related to epidemic cholera, as occurred in Zimbabwe, thereby providing an early warning system. Since cholera cannot be eradicated because the causative agent, Vibrio cholerae, is autochthonous to the aquatic environment, prediction of conditions favorable for its growth and estimation of risks of triggering the disease in a given population can be used to alert responders, potentially decreasing infection and saving lives.

Segmentation and sub-cellular feature-based analysis of microscopy images - Cardone, Antonio; Chalfoun, Joe; Peskin, Adele; Bajcsy, Peter; Kociolek, Marcin; Bhadriraju, Kiran; Brady, Mary (BioImage Informatics Conference, 2015)

Survey statistics of automated segmentations applied to optical imaging of mammalian cells - Bajcsy, Peter; Cardone, Antonio; Chalfoun, Joe; Halter, Michael; Juba, Derek; Kociolek, Marcin; Majurski, Michael; Peskin, Adele; Simon, Carl; Simon, Mylene; others (BMC bioinformatics, 2015)

A unified initiative to harness Earth's microbiomes - Alivisatos, A. P.; Blaser, M. J.; Brodie, E. L.; Chun, M.; Dangl, J. L.; Donohue, T. J.; Dorrestein, P. C.; Gilbert, J. A.; Green, J. L.; Jansson, J. K.; Knight, R.; Maxon, M. E.; et al. (Science, 2015)

Use of Environmental Parameters to Model Pathogenic Vibrios in Chesapeake Bay - Zaitchik, B. F.; Guikema, S. D.; Haley, B. J.; Taviani, E.; Chen, A.; Brown, M.E.; Huq, A.; Rita R Colwell (Journal of Environmental Informatics, 2015)
Although the transportation sector is a major contributor to urban air pollution and global climate change due to its substantial energy consumptions, previous studies for evacuation practices in this sector seldom took environmental consequences into account. As an attempt in event-related evacuation planning under uncertainty, this study proposed an emission-mitigation-oriented fuzzy evacuation management (emoFEM) model. Comprehensive considerations over system efficiency, environmental protection, economic cost and resource availability were incorporated within a general modeling formulation to facilitate evacuation management in a systematic and compromise manner. Vague and ambiguous information embedded within evacuation problems could be quantified and directly communicated into the optimization process, greatly improving conventional tools for evacuation management under uncertainty. The proposed emoFEM model was then applied to a hypothetic but representative case. Useful solutions were generated, which could help identify timely, safe and cost-effective evacuation schemes without significant disturbances over normal municipal traffic and environmental quality. The advantages of emoFEM were further revealed through comparing its solutions with those from its deterministic counterpart.

Global diarrhoea action plan needs integrated climate-based surveillance - Akanda, Ali S; Jutla, Antarpreet S; Rita R Colwell (The Lancet Global Health, 2014)

Vibrio metoecus sp. nov., a close relative of Vibrio cholerae isolated from coastal brackish ponds and clinical specimens - Kirchberger, P. C.; Turnsek, M.; Hunt, D. E.; Haley, B. J.; Rita R Colwell; Polz, M. F.; Tarr, C. L.; Boucher, Y. (INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY, 2014)

Vibrio ecology, pathogenesis, and evolution - Ceccarelli, Daniela; Rita R Colwell (Frontiers in Microbiology, 2014)

Microbial Community Profiling of Human Saliva Using Shotgun Metagenomic Sequencing - Hasan, Nur A.; Young, Brian A.; Minard-Smith, Angela T.; Saeed, Kelly; Li, Huai; Heizer, Esley M.; McMillan, Nancy J.; Isom, Richard; Abdullah, Abdul Shakur; Bornman, Daniel M.; Faith, Seth A.; Choi, Seon Young; et al. (PLoS ONE, 2014)
Human saliva is clinically informative of both oral and general health. Since next generation shotgun sequencing (NGS) is now widely used to identify and quantify bacteria, we investigated the bacterial flora of saliva microbiomes of two healthy volunteers and five datasets from the Human Microbiome Project, along with a control dataset containing short NGS reads from bacterial species representative of the bacterial flora of human saliva. GENIUS, a system designed to identify and quantify bacterial species using unassembled short NGS reads was used to identify the bacterial species comprising the microbiomes of the saliva samples and datasets. Results, achieved within minutes and at greater than 90% accuracy, showed more than 175 bacterial species comprised the bacterial flora of human saliva, including bacteria known to be commensal human flora but also Haemophilus influenzae, Neisseria meningitidis, Streptococcus pneumoniae, and Gamma proteobacteria. Basic Local Alignment Search Tool (BLASTn) analysis in parallel, reported ca. five times more species than those actually comprising the in silico sample. Both GENIUS and BLAST analyses of saliva samples identified major genera comprising the bacterial flora of saliva, but GENIUS provided a more precise description of species composition, identifying to strain in most cases and delivered results at least 10,000 times faster. Therefore, GENIUS offers a facile and accurate system for identification and quantification of bacterial species and/or strains in metagenomic samples.

Molecular diversity and predictability of Vibrio parahaemolyticus along the Georgian coastal zone of the Black Sea - Haley, Bradd J.; Kokashvili, Tamar; Tskshvediani, Ana; Janelidze, Nino; Mitaishvili, Nino; Grim, Christopher J.; Constantin_de_Magny, Guillaume; Chen, Arlene J.; Taviani, Elisa; Eliashvili, Tamar; Tediashvili, Marina; Whitehouse, Chris A.; et al. (Frontiers in Microbiology, 2014)
Vibrio parahaemolyticus is a leading cause of seafood-related gastroenteritis and is also an autochthonous member of marine and estuarine environments worldwide. One-hundred seventy strains of V. parahaemolyticus were isolated from water and plankton samples collected along the Georgian coast of the Black Sea during 28 months of sample collection. All isolated strains were tested for presence of tlh, trh, and tdh. A subset of strains were serotyped and tested for additional factors and markers of pandemicity. Twenty-six serotypes, five of which are clinically relevant, were identified. Although all 170 isolates were negative for tdh, trh, and the Kanagawa Phenomenon, 7 possessed the GS-PCR sequence and 27 the 850 bp sequence of V. parahaemolyticus pandemic strains. The V. parahaemolyticus population in the Black Sea was estimated to be genomically heterogeneous by rep-PCR and the serodiversity observed did not correlate with rep-PCR genomic diversity. Statistical modeling was used to predict presence of V. parahaemolyticus as a function of water temperature, with strongest concordance observed for Green Cape site samples (Percent of total variance = 70, P < 0.001). Results demonstrate a diverse population of V. parahaemolyticus in the Black Sea, some of which carry pandemic markers, with increased water temperature correlated to an increase in abundance of V. parahaemolyticus.

Occurrence in Mexico, 1998–2008, of Vibrio cholerae CTX + El Tor carrying an additional truncated CTX prophage - Alam, Munirul; Rashed, Shah M; Mannan, Shahnewaj Bin; Islam, Tarequl; Lizarraga-Partida, Marcial L.; Delgado, Gabriela; Morales-Espinosa, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Ohnishi, Makoto; Hasan, Nur A.; et al. (Proceedings of the National Academy of Sciences, 2014)

Phylodynamic Analysis of Clinical and Environmental Vibrio cholerae Isolates from Haiti Reveals Diversification Driven by Positive Selection - Azarian, Taj; Ali, Afsar; Johnson, Judith A.; Mohr, David; Prosperi, Mattia; Veras, Nazle M.; Jubair, Mohammed; Strickland, Samantha L.; Rashid, Mohammad H.; Alam, Meer T.; Weppelmann, Thomas A.; Katz, Lee S.; et al. (mBio, 2014)
Phylodynamic analysis of genome-wide single-nucleotide polymorphism (SNP) data is a powerful tool to investigate underlying evolutionary processes of bacterial epidemics. The method was applied to investigate a collection of 65 clinical and environmental isolates of Vibrio cholerae from Haiti collected between 2010 and 2012. Characterization of isolates recovered from environmental samples identified a total of four toxigenic V. cholerae O1 isolates, four non-O1/O139 isolates, and a novel nontoxigenic V. cholerae O1 isolate with the classical tcpA gene. Phylogenies of strains were inferred from genome-wide SNPs using coalescent-based demographic models within a Bayesian framework. A close phylogenetic relationship between clinical and environmental toxigenic V. cholerae O1 strains was observed. As cholera spread throughout Haiti between October 2010 and August 2012, the population size initially increased and then fluctuated over time. Selection analysis along internal branches of the phylogeny showed a steady accumulation of synonymous substitutions and a progressive increase of nonsynonymous substitutions over time, suggesting diversification likely was driven by positive selection. Short-term accumulation of nonsynonymous substitutions driven by selection may have significant implications for virulence, transmission dynamics, and even vaccine efficacy.

Validation of high throughput sequencing and microbial forensics applications - Budowle, Bruce; Connell, Nancy D; Bielecka-Oder, Anna; Rita R Colwell; Corbett, Cindi R; Fletcher, Jacqueline; Forsman, Mats; Kadavy, Dana R; Markotic, Alemka; Morse, Stephen A; Murch, Randall S; Sajantila, Antti; et al. (Investigative Genetics, 2014)
High throughput sequencing (HTS) generates large amounts of high quality sequence data for microbial genomics. The value of HTS for microbial forensics is the speed at which evidence can be collected and the power to characterize microbial-related evidence to solve biocrimes and bioterrorist events. As HTS technologies continue to improve, they provide increasingly powerful sets of tools to support the entire field of microbial forensics. Accurate, credible results allow analysis and interpretation, significantly influencing the course and/or focus of an investigation, and can impact the response of the government to an attack having individual, political, economic or military consequences. Interpretation of the results of microbial forensic analyses relies on understanding the performance and limitations of HTS methods, including analytical processes, assays and data interpretation. The utility of HTS must be defined carefully within established operating conditions and tolerances. Validation is essential in the development and implementation of microbial forensics methods used for formulating investigative leads attribution. HTS strategies vary, requiring guiding principles for HTS system validation. Three initial aspects of HTS, irrespective of chemistry, instrumentation or software are: 1) sample preparation, 2) sequencing, and 3) data analysis. Criteria that should be considered for HTS validation for microbial forensics are presented here. Validation should be defined in terms of specific application and the criteria described here comprise a foundation for investigators to establish, validate and implement HTS as a tool in microbial forensics, enhancing public safety and national security.

Viewing Marine Bacteria, Their Activity and Response to Environmental Drivers from Orbit - Grimes, D. Jay; Ford, Tim E.; Rita R Colwell; Baker-Austin, Craig; Martinez-Urtaza, Jaime; Subramaniam, Ajit; Capone, Douglas G. (Microbial Ecology, 2014)
Satellite-based remote sensing of marine microorganisms has become a useful tool in predicting human health risks associated with these microscopic targets. Early applications were focused on harmful algal blooms, but more recently methods have been developed to interrogate the ocean for bacteria. As satellite-based sensors have become more sophisticated and our ability to interpret information derived from these sensors has advanced, we have progressed from merely making fascinating pictures from space to developing process models with predictive capability. Our understanding of the role of marine microorganisms in primary production and global elemental cycles has been vastly improved as has our ability to use the combination of remote sensing data and models to provide early warning systems for disease outbreaks. This manuscript will discuss current approaches to monitoring cyanobacteria and vibrios, their activity and response to environmental drivers, and will also suggest future directions.

Current Topics in Microbiology and Immunology One Health: The Human-Animal-Environment Interfaces in Emerging Infectious Diseases The Human Environment Interface: Applying Ecosystem Concepts to Health - Preston, Nicholas D.; Daszak, Peter; Rita R Colwell (Springer Berlin Heidelberg, 2013)

Detection of Vibrio cholerae in environmental waters including drinking water reservoirs of Azerbaijan - Rashid, Ahmadov; Haley, Bradd J.; Rajabov, Mukhtar; Ahmadova, Sevinj; Gurbanov, Shair; Rita R Colwell; Huq, Anwar (Environmental Microbiology Reports, 2013)

Distribution of Virulence Genes in Clinical and Environmental Vibrio cholerae Strains in Bangladesh - Hasan, Nur A.; Ceccarelli, Daniela; Grim, Christopher J.; Taviani, Elisa; Choi, Jinna; Sadique, Abdus; Alam, Munirul; Siddique, Abul K.; Sack, R. Bradley; Huq, Anwar; Rita R Colwell (Applied and Environmental Microbiology, 2013)
Vibrio cholerae, an environmental organism, is a facultative human pathogen. Here, we report the virulence profiles, comprising 18 genetic markers, of 102 clinical and 692 environmental V. cholerae strains isolated in Bangladesh between March 2004 and January 2006, showing the variability of virulence determinants within the context of public health.

Drug response and genetic properties of Vibrio cholerae associated with endemic cholera in north-eastern Thailand, 2003-2011 - Chomvarin, C.; Johura, F.-T.; Mannan, S. B.; Jumroenjit, W.; Kanoktippornchai, B.; Tangkanakul, W.; Tantisuwichwong, N.; Huttayananont, S.; Watanabe, H.; Hasan, N. A.; Huq, A.; Cravioto, A.; et al. (Journal of Medical Microbiology, 2013)
Cholera, caused by Vibrio cholerae, results in significant morbidity and mortality worldwide, including Thailand. Representative V. cholerae strains associated with endemic cholera (n = 32), including strains (n = 3) from surface water sources, in Khon Kaen, Thailand (2003–2011), were subjected to microbiological, molecular and phylogenetic analyses. According to phenotypic and related genetic data, all tested V. cholerae strains belonged to serogroup O1, biotype El Tor (ET), Inaba (IN) or Ogawa (OG). All of the strains were sensitive to gentamicin and ciprofloxacin, while multidrug-resistant (MDR) strains showing resistance to erythromycin, tetracycline, trimethoprim/sulfamethoxazole and ampicillin were predominant in 2007. V. cholerae strains isolated before and after 2007 were non-MDR. All except six diarrhoeal strains possessed ctxA and ctxB genes and were toxigenic altered ET, confirmed by MAMA-PCR and DNA sequencing. Year-wise data revealed that V. cholerae INET strains isolated between 2003 and 2004, plus one strain isolated in 2007, lacked the RS1 sequence (rstC) and toxin-linked cryptic plasmid (TLC)-specific genetic marker, but possessed CTXCL prophage genes ctxB CL and rstR CL. A sharp genetic transition was noted, namely the majority of V. cholerae strains in 2007 and all in 2010 and 2011 were not repressor genotype rstR CL but instead were rstR ET, and all ctx + strains possessed RS1 and TLC-specific genetic markers. DNA sequencing data revealed that strains isolated since 2007 had a mutation in the tcpA gene at amino acid position 64 (N→S). Four clonal types, mostly of environmental origin, including subtypes, reflected genetic diversity, while distinct signatures were observed for clonally related, altered ET from Thailand, Vietnam and Bangladesh, confirmed by distinct subclustering patterns observed in the PFGE (NotI)-based dendrogram, suggesting that endemic cholera is caused by V. cholerae indigenous to Khon Kaen.

Engaging Actively with Issues in the Responsible Conduct of Science: Lessons from International Efforts Are Relevant for Undergraduate Education in the United States - Clements, John D.; Connell, Nancy D.; Dirks, Clarissa; El-Faham, Mohamed; Hay, Alastair; Heitman, Elizabeth; Stith, James H.; Bond, Enriqueta C.; Rita R Colwell; Anestidou, Lida; Husbands, Jo L.; Labov, Jay B. (CBE—Life Sciences Education, 2013)
Numerous studies are demonstrating that engaging undergraduate students in original research can improve their achievement in the science, technology, engineering, and mathematics (STEM) fields and increase the likelihood that some of them will decide to pursue careers in these disciplines. Associated with this increased prominence of research in the undergraduate curriculum are greater expectations from funders, colleges, and universities that faculty mentors will help those students, along with their graduate students and postdoctoral fellows, develop an understanding and sense of personal and collective obligation for responsible conduct of science (RCS). This Feature describes an ongoing National Research Council (NRC) project and a recent report about educating faculty members in culturally diverse settings (Middle East/North Africa and Asia) to employ active-learning strategies to engage their students and colleagues deeply in issues related to RCS. The NRC report describes the first phase of this project, which took place in Aqaba and Amman, Jordan, in September 2012 and April 2013, respectively. Here we highlight the findings from that report and our subsequent experience with a similar interactive institute in Kuala Lumpur, Malaysia. Our work provides insights and perspectives for faculty members in the United States as they engage undergraduate and graduate students, as well as postdoctoral fellows, to help them better understand the intricacies of and connections among various components of RCS. Further, our experiences can provide insights for those who may wish to establish “train-the-trainer” programs at their home institutions.

Environmental Factors Influencing Epidemic Cholera - Huq, Anwar; Hasan, Nur; Akanda, Ali; Whitcombe, Elizabeth; Rita R Colwell; Haley, Bradd; Alam, Munir; Jutla, Antarpreet; Sack, R. Bradley (The American Journal of Tropical Medicine and Hygiene, 2013)
Cholera outbreak following the earthquake of 2010 in Haiti has reaffirmed that the disease is a major public health threat. Vibrio cholerae is autochthonous to aquatic environment, hence, it cannot be eradicated but hydroclimatology-based prediction and prevention is an achievable goal. Using data from the 1800s, we describe uniqueness in seasonality and mechanism of occurrence of cholera in the epidemic regions of Asia and Latin America. Epidemic regions are located near regional rivers and are characterized by sporadic outbreaks, which are likely to be initiated during episodes of prevailing warm air temperature with low river flows, creating favorable environmental conditions for growth of cholera bacteria. Heavy rainfall, through inundation or breakdown of sanitary infrastructure, accelerates interaction between contaminated water and human activities, resulting in an epidemic. This causal mechanism is markedly different from endemic cholera where tidal intrusion of seawater carrying bacteria from estuary to inland regions, results in outbreaks.

Fostering advances in interdisciplinary climate science - Shaman, J.; Solomon, S.; Rita R Colwell; Field, C. B. (Proceedings of the National Academy of Sciences, 2013)

"I Want to Imagine How That Place Looks": Designing Technologies to Support Connectivity Between Africans Living Abroad and Home - Wyche, Susan P.; Marshini Chetty (SIGCHI '13, 2013)
Uneven access to Information and Communication Technologies (ICTs) in parts of the African continent make it challenging for some Africans who migrate to the U.S. to communicate with family members in their countries of origin. However, Internet access is becoming more widespread throughout the continent and this development presents an opportunity to explore how future interactive systems can support exchanges between families with members living in developed and less developed countries. To investigate these design possibilities we interviewed 27 African-born students, currently living in Virginia, U.S., and asked them how they used ICTs to connect with family members in their home countries. Our findings informed the development of a low-fidelity prototype that eight students lived with for four to five months. Findings from this deployment study motivate a discussion regarding features to include in interfaces designed to support transnational family communication. Features include personally meaningful imagery, country specific content, and the ability to monitor the weather and changing currency rates in migrants' countries of origin.
Keywords: diaspora communities; family communication; hci4d/ictd; Interaction design; research through design; transnational

Identification of bacteria in enrichment cultures of sulfate reducers in the Cariaco Basin water column employing Denaturing Gradient Gel Electrophoresis of 16S ribosomal RNA gene fragments - Bozo-Hurtado, Lorelei; García-Amado, M; Chistoserdov, Andrei; Varela, Ramon; Narvaez, J; Rita R Colwell; Suárez, Paula (Aquatic Biosystems, 2013)
Background The Cariaco Basin is characterized by pronounced and predictable vertical layering of microbial communities dominated by reduced sulfur species at and below the redox transition zone. Marine water samples were collected in May, 2005 and 2006, at the sampling stations A (10°30′ N, 64°40′ W), B (10°40′ N, 64°45′ W) and D (10°43’N, 64°32’W) from different depths, including surface, redox interface, and anoxic zones. In order to enrich for sulfate reducing bacteria (SRB), water samples were inoculated into anaerobic media amended with lactate or acetate as carbon source. To analyze the composition of enrichment cultures, we performed DNA extraction, PCR-DGGE, and sequencing of selected bands. Results DGGE results indicate that many bacterial genera were present that are associated with the sulfur cycle, including Desulfovibrio spp., as well as heterotrophs belonging to Vibrio, Enterobacter, Shewanella, Fusobacterium, Marinifilum, Mariniliabilia, and Spirochaeta. These bacterial populations are related to sulfur coupling and carbon cycles in an environment of variable redox conditions and oxygen availability. Conclusions In our studies, we found an association of SRB-like Desulfovibrio with Vibrio species and other genera that have a previously defined relevant role in sulfur transformation and coupling of carbon and sulfur cycles in an environment where there are variable redox conditions and oxygen availability. This study provides new information about microbial species that were culturable on media for SRB at anaerobic conditions at several locations and water depths in the Cariaco Basin.

Improving public transit accessibility for blind riders by crowdsourcing bus stop landmark locations with Google street view - Hara, Kotaro; Azenkot, Shiri; Campbell, Megan; Bennett, Cynthia L; Le, Vicki; Pannella, Sean; Moore, Robert; Minckler, Kelly; Ng, Rochelle H; Jon Froehlich (The 15th International ACM SIGACCESS Conference, 2013)
Abstract Low-vision and blind bus riders often rely on known physical landmarks to help locate and verify bus stop locations (eg., by searching for a shelter, bench, newspaper bin). However, there are currently few, if any, methods to determine this information a priori via ...

An Initial Study of Automatic Curb Ramp Detection with Crowdsourced Verification Using Google Street View Images - Hara, Kotaro; Sun, Jin; Chazan, Jonah; Jacobs, David; Jon Froehlich (First AAAI Conference on Human Computation and Crowdsourcing, 2013)
In our previous research, we examined whether minimally trained crowd workers could find, categorize, and assess sidewalk accessibility problems using Google Street View (GSV) images. This poster paper presents a first step towards combining automated methods ( e.g., machine vision-based curb ramp detectors) in concert with human computation to improve the overall scalability of our approach.

Modeling topic control to detect influence in conversations using nonparametric topic models - Nguyen, Viet-An; Jordan Boyd-Graber; Resnik, Philip; Cai, Deborah A; Midberry, Jennifer E; Wang, Yuanxin (Machine Learning, 2013)
Abstract Identifying influential speakers in multi-party conversations has been the focus of research in communication, sociology, and psychology for decades. It has been long acknowledged qualitatively that controlling the topic of a conversation is a sign of ...

A new integrative conjugative element detected in Haitian isolates of Vibrio cholerae non-O1/non-O139 - Ceccarelli, Daniela; Spagnoletti, Matteo; Hasan, Nur A.; Lansing, Stephanie; Huq, Anwar; Rita R Colwell (Research in Microbiology, 2013)
The presence of SXT/R391-related integrating conjugative elements (ICEs) in Vibrio cholerae O1 and non-O1/non-O139 isolated from clinical and environmental samples in Haiti in 2010 was studied. The main finding of this work was the identification of the novel ICEVchHai2 among closely related V. cholerae non-O1/non-O139 clinical strains. The mosaic structure of this element confirms the role of ICEs as efficient recombination systems whereby new genetic material can be acquired and exchanged, according V. cholerae strains new accessory functions.

Ocean Warming and Spread of Pathogenic Vibrios in the Aquatic Environment - Vezzulli, Luigi; Rita R Colwell; Pruzzo, Carla (Microbial Ecology, 2013)
Vibrios are among the most common bacteria that inhabit surface waters throughout the world and are responsible for a number of severe infections both in humans and animals. Several reports recently showed that human Vibrio illnesses are increasing worldwide including fatal acute diarrheal diseases, such as cholera, gastroenteritis, wound infections, and septicemia. Many scientists believe this increase may be associated with global warming and rise in sea surface temperature (SST), although not enough evidence is available to support a causal link between emergence of Vibrio infections and climate warming. The effect of increased SST in promoting spread of vibrios in coastal and brackish waters is considered a causal factor explaining this trend. Field and laboratory studies carried out over the past 40 years supported this hypothesis, clearly showing temperature promotes Vibrio growth and persistence in the aquatic environment. Most recently, a long-term retrospective microbiological study carried out in the coastal waters of the southern North Sea provided the first experimental evidence for a positive and significant relationship between SST and Vibrio occurrence over a multidecadal time scale. As a future challenge, macroecological studies of the effects of ocean warming on Vibrio persistence and spread in the aquatic environment over large spatial and temporal scales would conclusively support evidence acquired to date combined with studies of the impact of global warming on epidemiologically relevant variables, such as host susceptibility and exposure. Assessing a causal link between ongoing climate change and enhanced growth and spread of vibrios and related illness is expected to improve forecast and mitigate future outbreaks associated with these pathogens.

Parallel geometric classification of stem cells by their three-dimensional morphology - Juba,Derek; Cardone, Antonio; Ip, Cheuk Yiu; Simon Jr, Carl G; K Tison, Christopher; Kumar, Girish; Brady,Mary; Varshney, Amitabh (Computational Science & Discovery, 2013)

Primate Transcript and Protein Expression Levels Evolve Under Compensatory Selection Pressures - Zia Khan; Ford, Michael J.; Cusanovich, Darren A.; Mitrano, Amy; Pritchard, Jonathan K.; Gilad, Yoav (Science, 2013)
Changes in gene regulation have likely played an important role in the evolution of primates. Differences in messenger RNA (mRNA) expression levels across primates have often been documented; however, it is not yet known to what extent measurements of divergence in mRNA levels reflect divergence in protein expression levels, which are probably more important in determining phenotypic differences. We used high-resolution, quantitative mass spectrometry to collect protein expression measurements from human, chimpanzee, and rhesus macaque lymphoblastoid cell lines and compared them to transcript expression data from the same samples. We found dozens of genes with significant expression differences between species at the mRNA level yet little or no difference in protein expression. Overall, our data suggest that protein expression levels evolve under stronger evolutionary constraint than mRNA levels.Don't Ape Protein Variation Changes in DNA and messenger RNA (mRNA) expression levels have been used to estimate evolutionary changes between species. However protein expression levels may better reflect selection on divergent and constrained phenotypes. Khan et al. (p. 1100, published online 17 October; see the Perspective by Vogel) measured the differences among and within species between mRNA expression and protein levels in humans, chimpanzees, and rhesus macaques, identifying protein transcripts that seem to be under lineage-specific constraint between humans and chimpanzees.

Quantification of Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio cholerae in French Mediterranean coastal lagoons - Cantet, Franck; Hervio-Heath, Dominique; Caro, Audrey; Le Mennec, Cécile; Monteil, Caroline; Quéméré, Catherine; Jolivet-Gougeon, Anne; Rita R Colwell; Monfort, Patrick (Research in Microbiology, 2013)
Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio cholerae are human pathogens. Little is known about these Vibrio spp. in the coastal lagoons of France. The purpose of this study was to investigate their incidence in water, shellfish and sediment of three French Mediterranean coastal lagoons using the most probable number-polymerase chain reaction (MPN-PCR). In summer, the total number of V. parahaemolyticus in water, sediment, mussels and clams collected from the three lagoons varied from 1 to >1.1 × 103 MPN/l, 0.09 to 1.1 × 103 MPN/ml, 9 to 210 MPN/g and 1.5 to 2.1 MPN/g, respectively. In winter, all samples except mussels contained V. parahaemolyticus, but at very low concentrations. Pathogenic (tdh- or trh2-positive) V. parahaemolyticus were present in water, sediment and shellfish samples collected from these lagoons. The number of V. vulnificus in water, sediment and shellfish samples ranged from 1 to 1.1 × 103 MPN/l, 0.07 to 110 MPN/ml and 0.04 to 15 MPN/g, respectively, during summer. V. vulnificus was not detected during winter. V. cholerae was rarely detected in water and sediment during summer. In summary, results of this study highlight the finding that the three human pathogenic Vibrio spp. are present in the lagoons and constitute a potential public health hazard.

Segmenting time-lapse phase contrast images of adjacent NIH 3T3 cells. - Chalfoun, J; Kociolek, M; Dima, A; Halter, M; Cardone, Antonio; Peskin, A; Bajcsy, P; Brady, M. (Journal of microscopy, 2013)
We present a new method for segmenting phase contrast images of NIH 3T3 fibroblast cells that is accurate even when cells are physically in contact with each other. The problem of segmentation, when cells are in contact, poses a challenge to the accurate automation of cell counting, tracking and lineage modelling in cell biology. The segmentation method presented in this paper consists of (1) background reconstruction to obtain noise-free foreground pixels and (2) incorporation of biological insight about dividing and nondividing cells into the segmentation process to achieve reliable separation of foreground pixels defined as pixels associated with individual cells. The segmentation results for a time-lapse image stack were compared against 238 manually segmented images (8219 cells) provided by experts, which we consider as reference data. We chose two metrics to measure the accuracy of segmentation: the 'Adjusted Rand Index' which compares similarities at a pixel level between masks resulting from manual and automated segmentation, and the 'Number of Cells per Field' (NCF) which compares the number of cells identified in the field by manual versus automated analysis. Our results show that the automated segmentation compared to manual segmentation has an average adjusted rand index of 0.96 (1 being a perfect match), with a standard deviation of 0.03, and an average difference of the two numbers of cells per field equal to 5.39% with a standard deviation of 4.6%.
Keywords: Animals; Cell Adhesion; Cell Count; Cell Division; Cell Shape; Computational Biology; Fibroblasts; Image Processing, Computer-Assisted; Mice; Microscopy, Phase-Contrast; NIH 3T3 Cells; Reproducibility of results; Sensitivity and Specificity; Time-Lapse Imaging

Species composition of limnetic zooplankton from the southern coastal areas (Mathbaria and Bakerganj) in Bangladesh - Mozumder, Pronob K; Nahar, Samsun; Naser, M Niamul; Alam, Munirul; Huq, Anwar; Sack, R Bradley; Rita R Colwell (Journal of the Asiatic Society of Bangladesh, Science, 2013)
We studied the coastal zooplankton community structure of six waterbodies of Mathbaria and Bakerganj from January 2008 to June 2009. In total 35 zooplankton species were identified under 26 genera under 20 families under 8 orders from Mathbaria. Among them 6 were protozoans, 24 were rotifers, 3 were copepods, 1 was cladocerans and 1 was ostracods. From Bakergonj a total of 42 zooplankton species were identified under 23 genera under 17 Families under 7 orders. Among them 3 were protozoans, 25 were rotifers, 7 were copepods, 6 were cladocerans and 1 was ostracods. Results showed that abundance of rotifera group from both area was higher in Mathbaria (64.86%) and Bakerganj (60.98%) than other groups while abundance of ostracoda of Bakerganj area was lowest.

Specific and Non-Specific Protein Association in Solution: Computation of Solvent Effects and Prediction of First-Encounter Modes for Efficient Configurational Bias Monte Carlo Simulations - Cardone, Antonio; Pant, Harish; Hassan, Sergio A. (The Journal of Physical Chemistry B, 2013)

Understanding the impact of image quality on segmentation accuracy - Li-Baboud, Ya-Shian; Cardone, Antonio; Chalfoun, Joe; Bajcsy, Peter; Elliott, John (SPIE Newsroom, 2013)

A water marker monitored by satellites to predict seasonal endemic cholera - Jutla, Antarpreet; Akanda, Ali Shafqat; Huq, Anwar; Faruque, Abu Syed Golam; Rita R Colwell; Islam, Shafiqul (Remote Sensing Letters, 2013)
The ability to predict an occurrence of cholera, a water-related disease, offers a significant public health advantage. Satellite-based estimates of chlorophyll, a surrogate for plankton abundance, have been linked to cholera incidence. However, cholera bacteria can survive under a variety of coastal ecological conditions, thus constraining the predictive ability of the chlorophyll, since it provides only an estimate of greenness of seawater. Here, a new remote-sensing-based index is proposed: Satellite Water Marker (SWM), which estimates the condition of coastal water, based on observed variability in the difference between blue (412 nm) and green (555 nm) wavelengths that can be related to seasonal cholera incidence. The index is bounded between physically separable wavelengths for relatively clear (blue) and turbid (green) water. Using SWM, prediction of cholera with reasonable accuracy, at least two months in advance, can potentially be achieved in the endemic coastal regions.

An additional step in the transmission of Yersinia pestis? - Easterday, W Ryan; Kausrud, Kyrre L; Star, Bastiaan; Heier, Lise; Haley, Bradd J; Ageyev, Vladimir; Rita R Colwell; Stenseth, Nils Chr (The ISME Journal, 2012)
Plague, caused by the bacterium Yersinia pestis, is a mammalian vector-borne disease, transmitted by fleas that serve as the vector between rodent hosts. For many pathogens, including Y. pestis, there are strong evolutionary pressures that lead to a reduction in ‘useless genes’, with only those retained that reflect function in the specific environment inhabited by the pathogen. Genetic traits critical for survival and transmission between two environments, the rodent and the flea, are conserved in epizootic/epidemic plague strains. However, there are genes that remain conserved for which no function in the flea–rodent cycle has yet been observed, indicating an additional environment may exist in the transmission cycle of plague. Here, we present evidence for highly conserved genes that suggests a role in the persistence of Y. pestis after death of its host. Furthermore, maintenance of these genes points to Y. pestis traversing a post-mortem path between, and possibly within, epizootic periods and offering insight into mechanisms that may allow Y. pestis an alternative route of transmission in the natural environment.

BEAGLE: An Application Programming Interface and High-Performance Computing Library for Statistical Phylogenetics - Ayres,Daniel L; Darling,Aaron; Zwickl,Derrick J; Beerli,Peter; Holder,Mark T; Lewis,Paul O; Huelsenbeck,John P; Ronquist,Fredrik; Swofford,David L; Cummings, Michael P.; Rambaut,Andrew; Suchard,Marc A (Systematic BiologySyst Biol, 2012)
Phylogenetic inference is fundamental to our understanding of most aspects of the origin and evolution of life, and in recent years, there has been a concentration of interest in statistical approaches such as Bayesian inference and maximum likelihood estimation. Yet, for large data sets and realistic or interesting models of evolution, these approaches remain computationally demanding. High-throughput sequencing can yield data for thousands of taxa, but scaling to such problems using serial computing often necessitates the use of nonstatistical or approximate approaches. The recent emergence of graphics processing units (GPUs) provides an opportunity to leverage their excellent floating-point computational performance to accelerate statistical phylogenetic inference. A specialized library for phylogenetic calculation would allow existing software packages to make more effective use of available computer hardware, including GPUs. Adoption of a common library would also make it easier for other emerging computing architectures, such as field programmable gate arrays, to be used in the future. We present BEAGLE, an application programming interface (API) and library for high-performance statistical phylogenetic inference. The API provides a uniform interface for performing phylogenetic likelihood calculations on a variety of compute hardware platforms. The library includes a set of efficient implementations and can currently exploit hardware including GPUs using NVIDIA CUDA, central processing units (CPUs) with Streaming SIMD Extensions and related processor supplementary instruction sets, and multicore CPUs via OpenMP. To demonstrate the advantages of a common API, we have incorporated the library into several popular phylogenetic software packages. The BEAGLE library is free open source software licensed under the Lesser GPL and available from http://beagle-lib.googlecode.com. An example client program is available as public domain software.
Keywords: Bayesian phylogenetics; gpu; maximum likelihood; parallel computing

Biases from model assumptions in texture sub-cellular image segmentation - Cardone, Antonio; Amelot, Julien; Li-Baboud, Ya-Shian; Brady, Mary; Bajcsy, Peter (SPIE Newsroom, 2012)

A Blur-robust Descriptor with Applications to Face Recognition - Gopalan,R.; Taheri, S.; Turaga,P.; Chellapa, Rama (IEEE Transactions on Pattern Analysis and Machine Intelligence, 2012)
Understanding the effect of blur is an important problem in unconstrained visual analysis. We address this problem in the context of image-based recognition, by a fusion of image-formation models, and differential geometric tools. First, we discuss the space spanned by blurred versions of an image and then under certain assumptions, provide a differential geometric analysis of that space. More specifically, we create a subspace resulting from convolution of an image with a complete set of orthonormal basis functions of a pre-specified maximum size (that can represent an arbitrary blur kernel within that size), and show that the corresponding subspaces created from a clean image and its blurred versions are equal under the ideal case of zero noise, and some assumptions on the properties of blur kernels. We then study the practical utility of this subspace representation for the problem of direct recognition of blurred faces, by viewing the subspaces as points on the Grassmann manifold and present methods to perform recognition for cases where the blur is both homogenous and spatially varying. We empirically analyze the effect of noise, as well as the presence of other facial variations between the gallery and probe images, and provide comparisons with existing approaches on standard datasets.
Keywords: Blur; convolution; Face; face recognition; Grassmann manifold; Kernel; Manifolds; NOISE; PROBES

On the Centrality of Off-Line E-Cash to Concrete Partial Information Games - Choi, Seung Geol; Dana Dachman-Soled; Yung, Moti (Security and Cryptography for Networks, 2012)
Cryptography has developed numerous protocols for solving “partial information games” that are seemingly paradoxical. Some protocols are generic (e.g., secure multi-party computation) and others, due to the importance of the scenario they represent, are designed to solve a concrete problem directly. Designing efficient and secure protocols for (off-line) e-cash, e-voting, and e-auction are some of the most heavily researched concrete problems, representing various settings where privacy and correctness of the procedure is highly important. In this work, we initiate the exploration of the relationships among e-cash, e-voting and e-auction in the universal composability (UC) framework, by considering general variants of the three problems. In particular, we first define ideal functionalities for e-cash, e-voting, and e-auction, and then give a construction of a protocol that UC-realizes the e-voting (resp., e-auction) functionality in the e-cash hybrid model. This (black-box) reducibility demonstrates the centrality of off-line e-cash and implies that designing a solution to e-cash may bear fruits in other areas. Constructing a solution to one protocol problem based on a second protocol problem has been traditional in cryptography, but typically has concentrated on building complex protocols on simple primitives (e.g., secure multi-party computation from Oblivious Transfer, signature from one-way functions, etc.). The novelty here is reducibility among mature protocols and using the ideal functionality as a design tool in realizing other ideal functionalities. We suggest this new approach, and we only consider the very basic general properties from the various primitives to demonstrate its viability. Namely, we only consider the basic coin e-cash model, the e-voting that is correct and private and relies on trusted registration, and e-auction relying on a trusted auctioneer. Naturally, relationships among protocols with further properties (i.e., extended functionalities), using the approach advocated herein, are left as open questions.
Keywords: Computer Appl. in Administrative Data Processing; Computer Communication Networks; Data Encryption; Management of Computing and Information Systems; Systems and Data Security

Computational Extractors and Pseudorandomness - Dana Dachman-Soled; Gennaro, Rosario; Krawczyk, Hugo; Malkin, Tal (Theory of Cryptography, 2012)
Computational extractors are efficient procedures that map a source of sufficiently high min-entropy to an output that is computationally indistinguishable from uniform. By relaxing the statistical closeness property of traditional randomness extractors one hopes to improve the efficiency and entropy parameters of these extractors, while keeping their utility for cryptographic applications. In this work we investigate computational extractors and consider questions of existence and inherent complexity from the theoretical and practical angles, with particular focus on the relationship to pseudorandomness. An obvious way to build a computational extractor is via the “extract-then-prg” method: apply a statistical extractor and use its output to seed a PRG. This approach carries with it the entropy cost inherent to implementing statistical extractors, namely, the source entropy needs to be substantially higher than the PRG’s seed length. It also requires a PRG and thus relies on one-way functions. We study the necessity of one-way functions in the construction of computational extractors and determine matching lower and upper bounds on the “black-box efficiency” of generic constructions of computational extractors that use a one-way permutation as an oracle. Under this efficiency measure we prove a direct correspondence between the complexity of computational extractors and that of pseudorandom generators, showing the optimality of the extract-then-prg approach for generic constructions of computational extractors and confirming the intuition that to build a computational extractor via a PRG one needs to make up for the entropy gap intrinsic to statistical extractors. On the other hand, we show that with stronger cryptographic primitives one can have more entropy- and computationally-efficient constructions. In particular, we show a construction of a very practical computational extractor from any weak PRF without resorting to statistical extractors.
Keywords: Algorithm Analysis and Problem Complexity; Coding and Information Theory; Computer Communication Networks; Data Encryption; Math Applications in Computer Science; Systems and Data Security

Conversion of viable but nonculturable enteric bacteria to culturable by co‐culture with eukaryotic cells - Senoh,Mitsutoshi; Ghosh‐Banerjee,Jayeeta; Ramamurthy,Thandavarayan; Rita R Colwell; Miyoshi,Shin-ichi; Nair,G. Balakrish; Takeda,Yoshifumi (Microbiology and Immunology, 2012)
Viable but nonculturable (VBNC) Vibrio cholerae non-O1/non-O139, V. parahaemolyticus, enterohemorrhagic Escherichia coli, enterotoxigenic E. coli, enteropathogenic E. coli, Shigella flexneri, and Salmonella enterica were converted to the culturable state by co-culture with selected eukaryotic cells, e.g., HT-29, Caco-2, T84, HeLa, Intestine 407, and CHO cells.
Keywords: conversion to culturability; enteric bacteria; viable but nonculturable

Deep Sequencing of the Oral Microbiome Reveals Signatures of Periodontal Disease - Liu,B.; Faller, L.L.; Klitgord, N.; Mazumdar, V.; Ghodsi,M.; Sommer, D.D.; Gibbons, T.R.; Treangen, T.J.; Chang, Y.C.; Li,S. (PloS one, 2012)
The oral microbiome, the complex ecosystem of microbes inhabiting the human mouth, harbors several thousands of bacterial types. The proliferation of pathogenic bacteria within the mouth gives rise to periodontitis, an inflammatory disease known to also constitute a risk factor for cardiovascular disease. While much is known about individual species associated with pathogenesis, the system-level mechanisms underlying the transition from health to disease are still poorly understood. Through the sequencing of the 16S rRNA gene and of whole community DNA we provide a glimpse at the global genetic, metabolic, and ecological changes associated with periodontitis in 15 subgingival plaque samples, four from each of two periodontitis patients, and the remaining samples from three healthy individuals. We also demonstrate the power of whole-metagenome sequencing approaches in characterizing the genomes of key players in the oral microbiome, including an unculturable TM7 organism. We reveal the disease microbiome to be enriched in virulence factors, and adapted to a parasitic lifestyle that takes advantage of the disrupted host homeostasis. Furthermore, diseased samples share a common structure that was not found in completely healthy samples, suggesting that the disease state may occupy a narrow region within the space of possible configurations of the oral microbiome. Our pilot study demonstrates the power of high-throughput sequencing as a tool for understanding the role of the oral microbiome in periodontal disease. Despite a modest level of sequencing (~2 lanes Illumina 76 bp PE) and high human DNA contamination (up to ~90%) we were able to partially reconstruct several oral microbes and to preliminarily characterize some systems-level differences between the healthy and diseased oral microbiomes.

Detection, Isolation, and Identification of Vibrio cholerae from the Environment - Huq, Anwar; Haley, Bradd J.; Taviani, Elisa; Chen, Arlene; Hasan, Nur A.; Rita R Colwell (Current Protocols in Microbiology, 2012)
Recent molecular advances in microbiology have greatly improved the detection of bacterial pathogens in the environment. These improvements and a downward trend in the cost of molecular detection methods have contributed to increased frequency of detection of pathogenic microorganisms where traditional culture‐based detection methods have failed. Culture methods also have been greatly improved, and the confluence of the two suites of methods provides a powerful tool for detection, isolation, and characterization of pathogens. While molecular detection provides data on the presence and type of pathogens, culturing methods allow a researcher to preserve the organism of interest for “‐omics” studies, such as genomic, metabolomic, secretomic, and transcriptomic analysis, which are rapidly becoming more affordable. This has yielded a clearer understanding of the ecology and epidemiology of microorganisms that cause disease. In this unit, we present commonly accepted methods for isolation, detection, and characterization of V. cholerae, providing more extensive knowledge of the ecology and epidemiology of this organism. This unit has been fully revised and updated from the earlier version with the latest knowledge and additional information not previously included. Curr. Protoc. Microbiol. 26:6A.5.1‐6A.5.51. © 2012 by John Wiley & Sons, Inc.

Dictionary-based Face Recognition Under Variable Lighting and Pose - Patel, Vishal M.; Wu,T.; Biswas,S.; Phillips,P.; Chellapa, Rama (IEEE Transactions on Information Forensics and Security, 2012)
We present a face recognition algorithm based on simultaneous sparse approximations under varying illumination and pose. A dictionary is learned for each class based on given training examples which minimizes the representation error with a sparseness constraint. A novel test image is projected onto the span of the atoms in each learned dictionary. The resulting residual vectors are then used for classification. To handle variations in lighting conditions and pose, an image relighting technique based on pose-robust albedo estimation is used to generate multiple frontal images of the same person with variable lighting. As a result, the proposed algorithm has the ability to recognize human faces with high accuracy even when only a single or a very few images per person are provided for training. The efficiency of the proposed method is demonstrated using publicly available databases and it is shown that this method is efficient and can perform significantly better than many competitive face recognition algorithms.
Keywords: Biometrics; dictionary learning; face recognition; illumination variation,; outlier rejection

Dimension-independent multi-resolution morse complexes - De Floriani, Leila; Čomić,L. (Computers & Graphics, 2012)

Disaggregated water sensing from a single, pressure-based sensor: An extended analysis of HydroSense using staged experiments - Larson,Eric; Jon Froehlich; Campbell,Tim; Haggerty,Conor; Atlas,Les; Fogarty,James; Patel,Shwetak N. (Pervasive and Mobile Computing, 2012)
We present an extended analysis of our previous work on the HydroSense technology, which is a low-cost and easily installed single-point sensor of pressure for automatically disaggregating water usage activities in the home (Froehlich et al., 2009 [53]). We expand upon this work by providing a survey of existing and emerging water disaggregation techniques, a more comprehensive description of the theory of operation behind our approach, and an expanded analysis section that includes hot versus cold water valve usage classification and a comparison between two classification approaches: the template-based matching scheme used in Froehlich et al. (2009) [53] and a new stochastic approach using a Hidden Markov Model. We show that both are successful in identifying valve- and fixture-level water events with greater than 90% accuracies. We conclude with a discussion of the limitations in our experimental methodology and open problems going forward.
Keywords: Activity sensing; H1.2; H5.2; Infrastructure-mediated sensing; Sensors; Water usage

Ecology of Vibrio parahaemolyticus and Vibrio vulnificus in the Coastal and Estuarine Waters of Louisiana, Maryland, Mississippi, and Washington (United States) - Johnson, Crystal N.; Bowers, John C.; Griffitt, Kimberly J.; Molina, Vanessa; Clostio, Rachel W.; Pei, Shaofeng; Laws, Edward; Paranjpye, Rohinee N.; Strom, Mark S.; Chen, Arlene; Hasan, Nur A.; Huq, Anwar; et al. (Applied and Environmental Microbiology, 2012)
Vibrio parahaemolyticus and Vibrio vulnificus, which are native to estuaries globally, are agents of seafood-borne or wound infections, both potentially fatal. Like all vibrios autochthonous to coastal regions, their abundance varies with changes in environmental parameters. Sea surface temperature (SST), sea surface height (SSH), and chlorophyll have been shown to be predictors of zooplankton and thus factors linked to vibrio populations. The contribution of salinity, conductivity, turbidity, and dissolved organic carbon to the incidence and distribution of Vibrio spp. has also been reported. Here, a multicoastal, 21-month study was conducted to determine relationships between environmental parameters and V. parahaemolyticus and V. vulnificus populations in water, oysters, and sediment in three coastal areas of the United States. Because ecologically unique sites were included in the study, it was possible to analyze individual parameters over wide ranges. Molecular methods were used to detect genes for thermolabile hemolysin (tlh), thermostable direct hemolysin (tdh), and tdh-related hemolysin (trh) as indicators of V. parahaemolyticus and the hemolysin gene vvhA for V. vulnificus. SST and suspended particulate matter were found to be strong predictors of total and potentially pathogenic V. parahaemolyticus and V. vulnificus. Other predictors included chlorophyll a, salinity, and dissolved organic carbon. For the ecologically unique sites included in the study, SST was confirmed as an effective predictor of annual variation in vibrio abundance, with other parameters explaining a portion of the variation not attributable to SST.

Efficient Password Authenticated Key Exchange via Oblivious Transfer - Canetti, Ran; Dana Dachman-Soled; Vaikuntanathan, Vinod; Wee, Hoeteck (Public Key Cryptography – PKC 2012, 2012)
We present a new framework for constructing efficient password authenticated key exchange (PAKE) protocols based on oblivious transfer (OT). Using this framework, we obtain: an efficient and simple UC-secure PAKE protocol that is secure against adaptive corruptions without erasures. efficient and simple PAKE protocols under the Computational Diffie-Hellman (CDH) assumption and the hardness of factoring. (Previous efficient constructions rely on hash proof systems, which appears to be inherently limited to decisional assumptions.) All of our constructions assume a common reference string (CRS) but do not rely on random oracles.
Keywords: adaptive security; Algorithm Analysis and Problem Complexity; Computer Communication Networks; Data Encryption; Discrete Mathematics in Computer Science; Management of Computing and Information Systems; oblivious transfer; Password Authenticated Key Exchange; search assumptions; Systems and Data Security; UC security

Exploiting sparseness in de novo genome assembly - Ye, C.; Ma, Z.S.; Cannon, C.H.; Pop, Mihai; Yu, D.W. (BMC bioinformatics, 2012)
The very large memory requirements for the construction of assembly graphs for de novo genome assembly limit current algorithms to super-computing environments.In this paper, we demonstrate that constructing a sparse assembly graph which stores only a small fraction of the observed k-mers as nodes and the links between these nodes allows the de novo assembly of even moderately-sized genomes (~500 M) on a typical laptop computer. We implement this sparse graph concept in a proof-of-principle software package, SparseAssembler, utilizing a new sparse k-mer graph structure evolved from the de Bruijn graph. We test our SparseAssembler with both simulated and real data, achieving ~90% memory savings and retaining high assembly accuracy, without sacrificing speed in comparison to existing de novo assemblers.

Face Identification Using Large Feature Sets - Schwartz, W.R.; Guo,Huimin; Choi,Jonghyun; Davis, Larry S. (Image Processing, IEEE Transactions on, 2012)
With the goal of matching unknown faces against a gallery of known people, the face identification task has been studied for several decades. There are very accurate techniques to perform face identification in controlled environments, particularly when large numbers of samples are available for each face. However, face identification under uncontrolled environments or with a lack of training data is still an unsolved problem. We employ a large and rich set of feature descriptors (with more than 70 000 descriptors) for face identification using partial least squares to perform multichannel feature weighting. Then, we extend the method to a tree-based discriminative structure to reduce the time required to evaluate probe samples. The method is evaluated on Facial Recognition Technology (FERET) and Face Recognition Grand Challenge (FRGC) data sets. Experiments show that our identification method outperforms current state-of-the-art results, particularly for identifying faces acquired across varying conditions.
Keywords: (mathematics); approximations; trees; challenge; data; data; tree-based; discriminative; environments; face; feature; FERET; FRGC; grand; identification; least; recognition; recognition; least; sets; face; sets; facial; squares; squares; training; structure; uncontrolled; task; face; technology; multichannel; weighting; partial

Fast track article: Disaggregated water sensing from a single, pressure-based sensor: An extended analysis of HydroSense using staged experiments - Larson,Eric; Jon Froehlich; Campbell,Tim; Haggerty,Conor; Atlas,Les; Fogarty,James; Patel,Shwetak N. (Pervasive Mob. Comput., 2012)
We present an extended analysis of our previous work on the HydroSense technology, which is a low-cost and easily installed single-point sensor of pressure for automatically disaggregating water usage activities in the home (Froehlich et al., 2009 [53]). We expand upon this work by providing a survey of existing and emerging water disaggregation techniques, a more comprehensive description of the theory of operation behind our approach, and an expanded analysis section that includes hot versus cold water valve usage classification and a comparison between two classification approaches: the template-based matching scheme used in Froehlich et al. (2009) [53] and a new stochastic approach using a Hidden Markov Model. We show that both are successful in identifying valve- and fixture-level water events with greater than 90% accuracies. We conclude with a discussion of the limitations in our experimental methodology and open problems going forward.
Keywords: Activity sensing; H1.2; H5.2; Infrastructure-mediated sensing; Sensors; Water usage

A framework for human microbiome research - Methé, B.A.; Nelson,K. E; Pop, Mihai; Creasy, H.H.; Giglio, M.G.; Huttenhower, C.; Gevers, D.; Petrosino, J.F.; Abubucker, S.; Badger, J.H. (Nature, 2012)
A variety of microbial communities and their genes (the microbiome) exist throughout the human body, with fundamental roles in human health and disease. The National Institutes of Health (NIH)-funded Human Microbiome Project Consortium has established a population-scale framework to develop metagenomic protocols, resulting in a broad range of quality-controlled resources and data including standardized methods for creating, processing and interpreting distinct types of high-throughput metagenomic data available to the scientific community. Here we present resources from a population of 242 healthy adults sampled at 15 or 18 body sites up to three times, which have generated 5,177 microbial taxonomic profiles from 16S ribosomal RNA genes and over 3.5 terabases of metagenomic sequence so far. In parallel, approximately 800 reference strains isolated from the human body have been sequenced. Collectively, these data represent the largest resource describing the abundance and variety of the human microbiome, while providing a framework for current and future studies.

Genetic characteristics of drug-resistant Vibrio cholerae O1 causing endemic cholera in Dhaka, 2006-2011 - Rashed, S. M.; Mannan, S. B.; Johura, F.-T.; Islam, M. T.; Sadique, A.; Watanabe, H.; Sack, R. B.; Huq, A.; Rita R Colwell; Cravioto, A.; Alam, M. (Journal of Medical Microbiology, 2012)
Vibrio cholerae O1 biotype El Tor (ET), causing the seventh cholera pandemic, was recently replaced in Bangladesh by an altered ET possessing ctxB of the Classical (CL) biotype, which caused the first six cholera pandemics. In the present study, V. cholerae O1 strains associated with endemic cholera in Dhaka between 2006 and 2011 were analysed for major phenotypic and genetic characteristics. Of 54 representative V. cholerae isolates tested, all were phenotypically ET and showed uniform resistance to trimethoprim/sulfamethoxazole (SXT) and furazolidone (FR). Resistance to tetracycline (TE) and erythromycin (E) showed temporal fluctuation, varying from year to year, while all isolates were susceptible to gentamicin (CN) and ciprofloxacin (CIP). Year-wise data revealed erythromycin resistance to be 33.3 % in 2006 and 11 % in 2011, while tetracycline resistance accounted for 33, 78, 0, 100 and 27 % in 2006, 2007, 2008, 2009 and 2010, respectively; interestingly, all isolates tested were sensitive to TE in 2011, as observed in 2008. All V. cholerae isolates tested possessed genetic elements such as SXT, ctxAB, tcpA ET, rstR ET and rtxC; none had IntlI (Integron I). Double mismatch amplification mutation assay (DMAMA)-PCR followed by DNA sequencing and analysis of the ctxB gene revealed a point mutation at position 58 (C→A), which has resulted in an amino acid substitution from histidine (H) to asparagine (N) at position 20 (genotype 7) since 2008. Although the multi-resistant strains having tetracycline resistance showed minor genetic divergence, V. choleraestrains were clonal, as determined by a PFGE (NotI)-based dendrogram. This study shows 2008–2010 to be the time of transition from ctxB genotype 1 to genotype 7 in V. cholerae ET causing endemic cholera in Dhaka, Bangladesh.

Genomic analysis of ICE Vch Ban8: An atypical genetic element in Vibrio cholerae - Taviani, Elisa; Spagnoletti, Matteo; Ceccarelli, Daniela; Haley, Bradd J.; Hasan, Nur A.; Chen, Arlene; Colombo, Mauro M.; Huq, Anwar; Rita R Colwell (FEBS Letters, 2012)
Genomic islands (GIs) and integrative conjugative elements (ICEs) are major players in bacterial evolution since they encode genes involved in adaptive functions of medical or environmental importance. Here we performed the genomic analysis of ICEVchBan8, an unusual ICE found in the genome of a clinical non‐toxigenic Vibrio cholerae O37 isolate. ICEVchBan8 shares most of its genetic structure with SXT/R391 ICEs. However, this ICE codes for a different integration/excision module is located at a different insertion site, and part of its genetic cargo shows homology to other pathogenicity islands of V. cholerae.

Genomic diversity of 2010 Haitian cholera outbreak strains - Hasan, N. A.; Choi, S. Y.; Eppinger, M.; Clark, P. W.; Chen, A.; Alam, M.; Haley, B. J.; Taviani, E.; Hine, E.; Su, Q.; Tallon, L. J.; Prosper, J. B.; et al. (Proceedings of the National Academy of Sciences, 2012)

Gradient-based Image Recovery Methods from Incomplete Fourier Measurements - Patel, Vishal M.; Maleh,R.; Gilbert,A. C; Chellapa, Rama (IEEE Transactions on Image Processing, 2012)
A major problem in imaging applications such as Magnetic Resonance Imaging (MRI) and Synthetic Aperture Radar (SAR) is the task of trying to reconstruct an image with the smallest possible set of Fourier samples, every single one of which has a potential time and/or power cost. The theory of Compressive Sensing (CS) points to ways of exploiting inherent sparsity in such images in order to achieve accurate recovery using sub- Nyquist sampling schemes. Traditional CS approaches to this problem consist of solving total-variation minimization programs with Fourier measurement constraints or other variations thereof. This paper takes a different approach: Since the horizontal and vertical differences of a medical image are each more sparse or compressible than the corresponding total-variational image, CS methods will be more successful in recovering these differences individually. We develop an algorithm called GradientRec that uses a CS algorithm to recover the horizontal and vertical gradients and then estimates the original image from these gradients. We present two methods of solving the latter inverse problem: one based on least squares optimization and the other based on a generalized Poisson solver. After a thorough derivation of our complete algorithm, we present the results of various experiments that compare the effectiveness of the proposed method against other leading methods.
Keywords: Compressed sensing; Fourier transforms; Image coding; Image edge detection; Image reconstruction; L1–minimization; minimization; Noise measurement; OPTIMIZATION; Poisson solver; Sparse recovery; Total variation; TV

Gripper synthesis for indirect manipulation of cells using Holographic Optical Tweezers - Chowdhury,Sagar; Svec,Petr; Wang,Chenlu; Losert,Wolfgang; Gupta, Satyandra K. (2012)
Optical Tweezers (OT) are used for highly accurate manipulations of biological cells. However, the direct exposure of cells to focused laser beam may negatively influence their biological functions. In order to overcome this problem, we generate multiple optical traps to grab and move a 3D ensemble of inert particles such as silica microspheres to act as a reconfigurable gripper for a manipulated cell. The relative positions of the microspheres are important in order for the gripper to be robust against external environmental forces and the exposure of high intensity laser on the cell to be minimized. In this paper, we present results of different gripper configurations, experimentally tested using our OT setup, that provide robust gripping as well as minimize laser intensity experienced by the cell. We developed a computational approach that allowed us to perform preliminary modeling and synthesis of the gripper configurations. The gripper synthesis is cast as a multi-objective optimization problem.

Individuals among commuters: Building personalised transport information services from fare collection systems - Lathia,N.; Smith,C.; Jon Froehlich; Capra,L. (Pervasive and Mobile Computing, 2012)

InterPro in 2011: new developments in the family and domain prediction database. - Hunter, Sarah; Jones, Philip; Mitchell, Alex; Apweiler, Rolf; Attwood, Teresa K; Bateman, Alex; Bernard, Thomas; Binns, David; Bork, Peer; Burge, Sarah; de Castro, Edouard; Coggill, Penny; et al. (Nucleic Acids Res, 2012)
InterPro (http://www.ebi.ac.uk/interpro/) is a database that integrates diverse information about protein families, domains and functional sites, and makes it freely available to the public via Web-based interfaces and services. Central to the database are diagnostic models, known as signatures, against which protein sequences can be searched to determine their potential function. InterPro has utility in the large-scale analysis of whole genomes and meta-genomes, as well as in characterizing individual protein sequences. Herein we give an overview of new developments in the database and its associated software since 2009, including updates to database content, curation processes and Web and programmatic interfaces.
Keywords: Databases, Protein; Protein Structure, Tertiary; Proteins; Sequence Analysis, Protein; software; Terminology as Topic; User-Computer Interface

Vibrio Cholerae Classical Biotype Strains Reveal Distinct Signatures in Mexico - Alam,Munirul; Islam,M. Tarequl; Rashed,Shah Manzur; Johura,Fatema-Tuz; Bhuiyan,Nurul A.; Delgado,Gabriela; Morales,Rosario; Mendez,Jose Luis; Navarro,Armando; Watanabe,Haruo; Hasan,Nur-A.; Rita R Colwell; et al. (Journal of Clinical Microbiology, 2012)
Vibrio cholerae O1 Classical (CL) biotype caused the 5th and 6th, and probably the earlier cholera pandemics, before the El Tor (ET) biotype initiated the 7th pandemic in Asia in the 1970's by completely displacing the CL biotype. Although the CL biotype was thought to be extinct in Asia, and it had never been reported from Latin America, V. cholerae CL and ET biotypes, including hybrid ET were found associated with endemic cholera in Mexico between 1991 and 1997. In this study, CL biotype strains isolated from endemic cholera in Mexico, between 1983 and 1997 were characterized in terms of major phenotypic and genetic traits, and compared with CL biotype strains isolated in Bangladesh between 1962 and 1989. According to sero- and bio-typing data, all V. cholerae strains tested had the major phenotypic and genotypic characteristics specific for the CL biotype. Antibiograms revealed the majority of the Bangladeshi strains to be resistant to trimethoprim/sulfamethoxazole, furazolidone, ampicillin, and gentamycin, while the Mexican strains were sensitive to all of these drugs, as well as to ciprofloxacin, erythromycin, and tetracycline. Pulsed-field gel electrophoresis (PFGE) of NotI-digested genomic DNA revealed characteristic banding patterns for all the CL biotype strains, although the Mexican strains differed with the Bangladeshi strains in 1-2 DNA bands. The difference may be subtle, but consistent, as confirmed by the sub-clustering patterns in the PFGE-based dendrogram, and can serve as regional signature, suggesting pre-1991 existence and evolution of the CL biotype strains in the Americas, independent from that of Asia.

Vibrio cholerae in a historically cholera-free country - Haley, Bradd J.; Chen, Arlene; Grim, Christopher J.; Clark, Philip; Diaz, Celia M; Taviani, Elisa; Hasan, Nur A.; Sancomb, Elizabeth; Elnemr, Wessam M; Islam, Muhammad A.; Huq, Anwar; Rita R Colwell; et al. (Environmental Microbiology Reports, 2012)
We report the autochthonous existence of Vibrio cholerae in coastal waters of Iceland, a geothermally active country where cholera is absent and has never been reported. Seawater, mussel and macroalgae samples were collected close to, and distant from, sites where geothermal activity causes a significant increase in water temperature during low tides. Vibrio cholerae was detected only at geothermal‐influenced sites during low‐tides. None of the V. cholerae isolates encoded cholera toxin (ctxAB) and all were non‐O1/non‐O139 serogroups. However, all isolates encoded other virulence factors that are associated with cholera as well as extra‐intestinal V. cholerae infections. The virulence factors were functional at temperatures of coastal waters of Iceland, suggesting an ecological role. It is noteworthy that V. cholerae was isolated from samples collected at sites distant from anthropogenic influence, supporting the conclusion that V. cholerae is autochthonous to the aquatic environment of Iceland.

Lithium: Event-Driven Network Control - Kim,H.; Voellmy,A.; Burnett,S.; Feamster, Nick; Clark,R. (Georgia Institute of Technology, 2012)
This paper introduces event-driven network control, a network control framework that makes networks easier to manage by automating many tasks that must currently be performed by manually modifying low-level, distributed, and complex device configuration. We identify four policy domains that inherently capture many events: time, user, history, and traffic flow. We then present Lithium, an event-driven network control framework that can implement policies expressed using these domains. Lithium can support policies that automatically react to a wide range of events, from fluctuations in traffic volumes to changes in the time of day. Lithium allows network operators to specify networkwide policies in terms of a high-level, event-driven policy model, as opposed to configuring individual network devices with low-level commands. To show that Lithium is practical, general, and applicable in different types of network scenarios, we have deployed Lithium in both a campus network and a home network and used it to implement more flexible and dynamic network policies. We also perform evaluations to show that Lithium introduces negligible overhead beyond a conventional OpenFlow-based control framework.

Local Segmentation of Touching Characters using Contour based Shape Decomposition - Kang,Le; David Doermann; Cao,Huiagu; Prasad,Rohit; Natarajan,Prem (Document Analysis Systems, 2012)
We propose a contour based shape decomposition approach that provides local segmentation of touching characters. The shape contour is linearized into edgelets and edgelets are merged into boundary fragments. Connection cost between boundary fragments is obtained by considering local smoothness, connection length and a stroke-level property Similar Stroke Rate. Samples of connections among boundary fragments are randomly generated and the one with the minimum global cost is selected to produce optimal segmentation of the shape. To obtain a binary segmentation using this approach, we make an iterative search for the parameters that yields two components on a shape. Experimental results on a number of synthetic shape images and the LTP dataset showed that this contour based shape decomposition technique is promising and it is effective on providing local segmentation of touching characters.

Long-term effects of ocean warming on the prokaryotic community: evidence from the vibrios - Vezzulli, Luigi; Brettar, Ingrid; Pezzati, Elisabetta; Reid, Philip C; Rita R Colwell; Höfle, Manfred G; Pruzzo, Carla (The ISME Journal, 2012)
The long-term effects of ocean warming on prokaryotic communities are unknown because of lack of historical data. We overcame this gap by applying a retrospective molecular analysis to the bacterial community on formalin-fixed samples from the historical Continuous Plankton Recorder archive, which is one of the longest and most geographically extensive collections of marine biological samples in the world. We showed that during the last half century, ubiquitous marine bacteria of the Vibrio genus, including Vibrio cholerae, increased in dominance within the plankton-associated bacterial community of the North Sea, where an unprecedented increase in bathing infections related to these bacteria was recently reported. Among environmental variables, increased sea surface temperature explained 45% of the variance in Vibrio data, supporting the view that ocean warming is favouring the spread of vibrios and may be the cause of the globally increasing trend in their associated diseases.

Modality and Negation in SIMT Use of Modality and Negation in Semantically-Informed Syntactic MT - Baker,Kathryn; Bloodgood,Michael; Dorr, Bonnie J; Callison-Burch,Chris; Filardo,Nathaniel W.; Piatko,Christine; Levin,Lori; Miller,Scott (Computational Linguistics, 2012)
This paper describes the resource- and system-building efforts of an eight-week Johns Hopkins University Human Language Technology Center of Excellence Summer Camp for Applied Language Exploration (SCALE-2009) on Semantically-Informed Machine Translation (SIMT). We describe a new modality/negation (MN) annotation scheme, the creation of a (publicly available) MN lexicon, and two automated MN taggers that we built using the annotation scheme and lexicon. Our annotation scheme isolates three components of modality and negation: a trigger (a word that conveys modality or negation), a target (an action associated with modality or negation) and a holder (an experiencer of modality). We describe how our MN lexicon was semi-automatically produced and we demonstrate that a structure-based MN tagger results in precision around 86% (depending on genre) for tagging of a standard LDC data set.

Occurrence of protozoans & their limnological relationships in some ponds of Mathbaria, Bangladesh - Mozumder,P. K.; Banu,M. A.; Naser,M. N.; Ali,M. S.; Alam,M.; Sack,R. B.; Rita R Colwell; Huq,A. (University Journal of Zoology, Rajshahi University, 2012)

Optimizing epidemic protection for socially essential workers - Barrett,Chris; Beckman,Richard; Bisset,Keith; Chen,Jiangzhuo; DuBois,Thomas; Eubank,Stephen; Kumar,V. S. Anil; Lewis,Bryan; Marathe,Madhav V.; Srinivasan, Aravind; Stretz,Paula E. (Proceedings of the 2nd ACM SIGHIT International Health Informatics Symposium, 2012)
Public-health policy makers have many tools to mitigate an epidemic's effects. Most related research focuses on the direct effects on those infected (in terms of health, life, or productivity). Interventions including treatment, prophylaxis, quarantine, and social distancing are well studied in this context. These interventions do not address indirect effects due to the loss of critical services and infrastructures when too many of those responsible for their day-to-day operations fall ill. We examine, both analytically and through simulation, the protection of such essential subpopulations by sequestering them, effectively isolating them into groups during an epidemic. We develop a framework for studying the benefits of sequestering and heuristics for when to sequester. We also prove a key property of sequestering placement which helps partition the subpopulations optimally. Thus we provide a first step toward determining how to allocate resources between the direct protection of a population, and protection of those responsible for critical services.
Keywords: epidemiology; OPTIMIZATION; public health informatics

Preparation and probing of coherent vibrational wave packets in the ground electronic state of HD^{+} - Bhattacharya, Rangana; Chatterjee, Souvik; Bhattacharyya, Shuvra S. (Physical Review A, 2012)
We have investigated the formation of coherent vibrational wave packets in the ground electronic state of HD+ on exposure to intense ultrashort laser pulses of wavelength 1060 nm. The effects of the duration and field strength of the pulse on the final composition of the residual bound nuclear wave packet generated by such impulsive excitations have been studied. The resulting wave packet is allowed to evolve freely on the potential surface for some time, after which a weak pulse of sufficiently large duration is used for probing its composition. This pulse can cause only single-photon dissociation. The simulations have been performed with different probe wavelengths for accessing information about different portions of the wave packet in the vibrational quantum number space. Our aim was to investigate the extent to which information obtained from the kinetic-energy spectra of the photofragments induced by the probe pulse can be correlated to the structure of the wave packet. Simple time-dependent perturbation calculations have also been performed for obtaining the relative strengths of photofragment signals arising from different vibrational levels due to wave-packet dissociation. A comparison with our numerical results indicates that though the general features of the photofragment kinetic-energy spectra from a wave packet are consistent with the perturbation theory results in the intensity regime studied, dynamical evolution during a long pulse can modify the relative heights of the kinetic-energy peaks through nonperturbative interactions in some cases.

Quantitative measurement of allele‐specific protein expression in a diploid yeast hybrid by LC‐MS - Zia Khan; Bloom, Joshua S.; Amini, Sasan; Singh, Mona; Perlman, David H.; Caudy, Amy A.; Kruglyak, Leonid (Molecular Systems Biology, 2012)
Understanding the genetic basis of gene regulatory variation is a key goal of evolutionary and medical genetics. Regulatory variation can act in an allele‐specific manner (cis‐acting) or it can affect both alleles of a gene (trans‐acting). Differential allele‐specific expression (ASE), in which the expression of one allele differs from another in a diploid, implies the presence of cis‐acting regulatory variation. While microarrays and high‐throughput sequencing have enabled genome‐wide measurements of transcriptional ASE, methods for measurement of protein ASE (pASE) have lagged far behind. We describe a flexible, accurate, and scalable strategy for measurement of pASE by liquid chromatography‐coupled mass spectrometry (LC‐MS). We apply this approach to a hybrid between the yeast species Saccharomyces cerevisiae and Saccharomyces bayanus. Our results provide the first analysis of the relative contribution of cis‐acting and trans‐acting regulatory differences to protein expression divergence between yeast species.Synopsis A novel strategy for the quantitative measurement of allele‐specific protein expression is used to infer the contributions of cis‐ and trans‐acting factors influencing the divergence of protein levels between yeast species. Rigorous experimental controls and analyses confirm the accuracy of the new strategy for the quantitative measurement of allele‐specific protein expression by high‐throughput mass spectrometry.Analysis of allele‐specific protein expression in an interspecies yeast hybrid and protein expression differences between species reveals that both cis‐effects and trans‐effects contribute to protein expression divergence between two yeast species, Saccharomyces cerevisiae and Saccharomyces bayanus.
Keywords: allele specific; divergence; mass spectrometry; protein expression; proteomics

Refactoring Network Infrastructure to Improve Manageability: A Case Study of Home Networking - Marshini Chetty; Feamster, Nick (SIGCOMM Comput. Commun. Rev., 2012)
Managing a home network is challenging because the underlying infrastructure is so complex. Existing interfaces either hide or expose the network's underlying complexity, but in both cases, the information that is shown does not necessarily allow a user to complete desired tasks. Recent advances in software defined networking, however, permit a redesign of the underlying network and protocols, potentially allowing designers to move complexity further from the user and, in some cases, eliminating it entirely. In this paper, we explore whether the choices of what to make visible to the user in the design of today's home network infrastructure, performance, and policies make sense. We also examine whether new capabilities for refactoring the network infrastructure - changing the underlying system without compromising existing functionality - should cause us to revisit some of these choices. Our work represents a case study of how co-designing an interface and its underlying infrastructure could ultimately improve interfaces for that infrastructure.
Keywords: home networking; management; Monitoring; software defined networking

Role of GbpA protein, an important virulence-related colonization factor, for Vibrio cholerae's survival in the aquatic environment - Stauder, Monica; Huq, Anwar; Pezzati, Elisabetta; Grim, Christopher J.; Ramoino, Paola; Pane, Luigi; Rita R Colwell; Pruzzo, Carla; Vezzulli, Luigi (Environmental Microbiology Reports, 2012)
Vibrio cholerae N‐acetyl glucosamine‐binding protein A (GbpA) is a chitin binding protein and a virulence factor involved in the colonization of human intestine. We investigated the distribution and genetic variations of gbpA in 488 V. cholerae strains of environmental and clinical origin, belonging to different serogroups and biotypes. We found that the gene is consistently present and highly conserved including an environmental V. cholerae‐related strain of ancestral origin. The gene was also consistently expressed in a number of representative V. cholerae strains cultured in laboratory aquatic microcosms under conditions simulating those found in temperate marine environments. Functional analysis carried out on V. cholerae O1 El Tor N16961 showed that GbpA is not involved in adhesion to inorganic surfaces but promotes interaction with environmental biotic substrates (plankton and bivalve hepatopancreas cells) representing known marine reservoir or host for the bacterium. It is suggested that the ability of GbpA to colonize human intestinal cells most probably originated from its primary function in the aquatic environment.

Role of Shrimp Chitin in the Ecology of Toxigenic Vibrio cholerae and Cholera Transmission - Nahar,Shamsun; Sultana,Marzia; Naser,M. Niamul; Nair,Gopinath B.; Watanabe,Haruo; Ohnishi,Makoto; Yamamoto,Shouji; Endtz,Hubert; Cravioto,Alejandro; Sack,R. Bradley; Hasan,Nur A.; Sadique,Abdus; et al. (Frontiers in Microbiology, 2012)
Seasonal plankton blooms correlate with occurrence of cholera in Bangladesh, although the mechanism of how dormant Vibrio cholerae, enduring interepidemic period in biofilms and plankton, initiates seasonal cholera is not fully understood. In this study, laboratory microcosms prepared with estuarine Mathbaria water (MW) samples supported active growth of toxigenic V. cholerae O1 up to 7 weeks as opposed to 6 months when microcosms were supplemented with dehydrated shrimp chitin chips (CC) as the single source of nutrient. Bacterial counting and detection of wbe and ctxA genes were done employing culture, direct fluorescent antibody (DFA) assay, and multiplex-polymerase chain reaction methods. In MW microcosm, the aqueous phase became clear as the non-culturable cells settled, whereas the aqueous phase of the MW–CC microcosm became turbid from bacterial growth stimulated by chitin. Bacterial chitin degradation and biofilm formation proceeded from an initial steady state to a gradually declining bacterial culturable count. V. cholerae within the microenvironments of chitin and chitin-associated biofilms remained metabolically active even in a high acidic environment without losing either viability or virulence. It is concluded that the abundance of chitin that occurs during blooms plays an important role in the aquatic life cycle of V. cholerae and, ultimately, in the seasonal transmission of cholera.

Secure multi-party computation of boolean circuits with applications to privacy in on-line marketplaces - Choi,S.; Hwang,K.W.; Katz, Jonathan; Malkin,T.; Rubenstein,D. (Topics in Cryptology–CT-RSA 2012, 2012)
Protocols for generic secure multi-party computation (MPC) generally come in two forms: they either represent the function being computed as a boolean circuit, or as an arithmetic circuit over a large field. Either type of protocol can be used for any function, but the choice of which protocol to use can have a significant impact on efficiency. The magnitude of the effect, however, has never been quantified.With this in mind, we implement the MPC protocol of Goldreich, Micali, and Wigderson [13], which uses a boolean representation and is secure against a semi-honest adversary corrupting any number of parties. We then consider applications of secure MPC in on-line marketplaces, where customers select resources advertised by providers and it is desired to ensure privacy to the extent possible. Problems here are more naturally formulated in terms of boolean circuits, and we study the performance of our MPC implementation relative to existing ones that use an arithmetic-circuit representation. Our protocol easily handles tens of customers/providers and thousands of resources, and outperforms existing implementations including FairplayMP [3], VIFF [11], and SEPIA [7].

Securing Circuits against Constant-Rate Tampering - Dana Dachman-Soled; Kalai, Yael Tauman (Advances in Cryptology – CRYPTO 2012, 2012)
We present a compiler that converts any circuit into one that remains secure even if a constant fraction of its wires are tampered with. Following the seminal work of Ishai et. al. (Eurocrypt 2006), we consider adversaries who may choose an arbitrary set of wires to corrupt, and may set each such wire to 0 or to 1, or may toggle with the wire. We prove that such adversaries, who continuously tamper with the circuit, can learn at most logarithmically many bits of secret information (in addition to black-box access to the circuit). Our results are information theoretic.
Keywords: circuit compiler; Computer Communication Networks; computers and society; Data Encryption; Discrete Mathematics in Computer Science; Management of Computing and Information Systems; PCP of proximity; side-channel attacks; Systems and Data Security; tampering

Sharpness Estimation for Document and Scene Images - Kumar,Jayant; Chen, Francine; David Doermann (International Conference on Pattern Recognition (ICPR 2012), 2012)
Images of document pages have different characteristics than images of natural scenes, and so the sharpness measures developed for natural scene images do not necessarily extend to document images primarily composed of text. We present an efficient and simple method for effectively estimating the sharpness/ blurriness of document images that also performs well on natural scenes. Our method can be used to predict the sharpness in scenarios where images are blurred due to camera-motion (or hand-shake), defocus, or inherent properties of the imaging system. The proposed method outperforms the perceptually-based, no-reference sharpness work of [1] and [4], which was shown to perform better than 14 other no-reference sharpness measures on the LIVE dataset.

Structure, function and diversity of the healthy human microbiome - Huttenhower, C.; Gevers, D.; Knight,R.; Abubucker, S.; Badger, J.H.; Chinwalla, A.T.; Creasy, H.H.; Earl, A.M.; Fitzgerald, M.G.; Fulton, R.S.; others (Nature, 2012)
Studies of the human microbiome have revealed that even healthy individuals differ remarkably in the microbes that occupy habitats such as the gut, skin and vagina. Much of this diversity remains unexplained, although diet, environment, host genetics and early microbial exposure have all been implicated. Accordingly, to characterize the ecology of human-associated microbial communities, the Human Microbiome Project has analysed the largest cohort and set of distinct, clinically relevant body habitats so far. We found the diversity and abundance of each habitat’s signature microbes to vary widely even among healthy subjects, with strong niche specialization both within and among individuals. The project encountered an estimated 81–99% of the genera, enzyme families and community configurations occupied by the healthy Western microbiome. Metagenomic carriage of metabolic pathways was stable among individuals despite variation in community structure, and ethnic/racial background proved to be one of the strongest associations of both pathways and microbes with clinical metadata. These results thus delineate the range of structural and functional configurations normal in the microbial communities of a healthy population, enabling future characterization of the epidemiology, ecology and translational applications of the human microbiome.

Sub-cellular feature detection and automated extraction of collocalized actin and myosin regions - Martineau, Justin; Mokashi,Ronil; Chapman, David; Grasso, Michael; Brady,Mary; Yesha,Yelena; Yesha,Yaacov; Cardone, Antonio; Dima, Alden (the 2nd ACM SIGHIT symposiumProceedings of the 2nd ACM SIGHIT symposium on International health informatics - IHI '12, 2012)

Systems and Methods for Energy Harvesting in a Contained Fluid Circuit - Campbell,Tim; Larson,Eric; Cohn, Gabriel; Alcaide,Ramses; Jon Froehlich; Patel,Shwetak (UNIVERSITY OF WASHINGTON THROUGH ITS CENTER FOR COMMERCIALIZATION, CAMPBELL, Tim, LARSON, Eric, COHN, Gabriel, ALCAIDE, Ramses, FROEHLICH, Jon, PATEL, Shwetak, 2012)
Systems and methods for harvesting energy from a closed fluid circuit, such as a water pipe system in a building. An energy harvester can be installed at a point in a water circuit and can generate energy from pressure differentials caused when a valve is opened or closed at any other point in the water circuit that is in fluid communication with the energy harvester. The energy can be used to power, for example, a sensor and/or a transmitter., L'invention concerne des systèmes et des procédés de collecte de l'énergie qui provient d'un circuit de fluide fermé, comme un système de conduites d'eau dans un immeuble. Un collecteur d'énergie peut être installé à un certain point au sein d'un circuit d'eau et peut générer de l'énergie à partir des différentiels de pression provoqués lorsqu'une soupape est ouverte ou fermée à n'importe quel autre point au sein du circuit d'eau qui est en communication fluidique avec le collecteur d'énergie. L'énergie peut être utilisée pour alimenter, par exemple, un capteur et/ou un émetteur.
Keywords: Systems and Methods for Energy Harvesting in a Contained Fluid Circuit

Temporal and Spatial Variability in the Distribution of Vibrio vulnificus in the Chesapeake Bay: A Hindcast Study - Banakar,V.; Constantin de Magny,G.; Jacobs,J.; Murtugudde,R.; Huq,A.; J. Wood,R.; Rita R Colwell (EcoHealth, 2012)
Vibrio vulnificus, an estuarine bacterium, is the causative agent of seafood-related gastroenteritis, primary septicemia, and wound infections worldwide. It occurs as part of the normal microflora of coastal marine environments and can be isolated from water, sediment, and oysters. Hindcast prediction was undertaken to determine spatial and temporal variability in the likelihood of occurrence of V. vulnificus in surface waters of the Chesapeake Bay. Hindcast predictions were achieved by forcing a multivariate habitat suitability model with simulated sea surface temperature and salinity in the Bay for the period between 1991 and 2005 and the potential hotspots of occurrence of V. vulnificus in the Chesapeake Bay were identified. The likelihood of occurrence of V. vulnificus during high and low rainfall years was analyzed. From results of the study, it is concluded that hindcast prediction yields an improved understanding of environmental conditions associated with occurrence of V. vulnificus in the Chesapeake Bay.

Towards event sequence representation, reasoning and visualization for EHR data - Tao,Cui; Wongsuphasawat,Krist; Clark,Kimberly; Plaisant, Catherine; Shneiderman, Ben; Chute,Christopher G. (Proceedings of the 2nd ACM SIGHIT International Health Informatics Symposium, 2012)
Efficient analysis of event sequences and the ability to answer time-related, clinically important questions can accelerate clinical research in several areas such as causality assessments, decision support systems, and retrospective studies. The Clinical Narrative Temporal Reasoning Ontology (CNTRO)-based system is designed for semantically representing, annotating, and inferring temporal relations and constraints for clinical events in Electronic Health Records (EHR) represented in both structured and unstructured ways. The LifeFlow system is designed to support an interactive exploration of event sequences using visualization techniques. The combination of the two systems will provide a comprehensive environment for users to visualize inferred temporal relationships from EHR data. This paper discusses our preliminary efforts on connecting the two systems and the benefits we envision from such an environment.
Keywords: ehr; semantic web; temporal relation reasoning; time trend visualization

You'Re Capped: Understanding the Effects of Bandwidth Caps on Broadband Use in the Home - Marshini Chetty; Banks, Richard; Brush, A.J.; Donner, Jonathan; Grinter, Rebecca (SIGCHI '12, 2012)
Bandwidth caps, a limit on the amount of data users can upload and download in a month, are common globally for both home and mobile Internet access. With caps, each bit of data consumed comes at a cost against a monthly quota or a running tab. Yet, relatively little work has considered the implications of this usage-based pricing model on the user experience. In this paper, we present results from a qualitative study of households living with bandwidth caps. Our findings suggest home users grapple with three uncertainties regarding their bandwidth usage: invisible balances, mysterious processes, and multiple users. We discuss how these uncertainties impact their usage and describe the potential for better tools to help monitor and manage data caps. We conclude that as a community we need to cater for users under Internet cost constraints.
Keywords: Bandwidth; bandwidth cap; data cap; Internet; metered use; pricing; usage-based billing; usage-based pricing

Accurate proteome-wide protein quantification from high-resolution 15N mass spectra - Zia Khan; Amini, Sasan; Bloom, Joshua S.; Ruse, Cristian; Caudy, Amy A.; Kruglyak, Leonid; Singh, Mona; Perlman, David H.; Tavazoie, Saeed (Genome Biology, 2011)
In quantitative mass spectrometry-based proteomics, the metabolic incorporation of a single source of 15N-labeled nitrogen has many advantages over using stable isotope-labeled amino acids. However, the lack of a robust computational framework for analyzing the resulting spectra has impeded wide use of this approach. We have addressed this challenge by introducing a new computational methodology for analyzing 15N spectra in which quantification is integrated with identification. Application of this method to an Escherichia coli growth transition reveals significant improvement in quantification accuracy over previous methods.PMID: 22182234

Active inference for retrieval in camera networks - Daozheng Chen; Bilgic,M.; Getoor, Lise; Jacobs, David W.; Mihalkova,L.; Tom Yeh (Person-Oriented Vision (POV), 2011 IEEE Workshop on, 2011)
We address the problem of searching camera network videos to retrieve frames containing specified individuals. We show the benefit of utilizing a learned probabilistic model that captures dependencies among the cameras. In addition, we develop an active inference framework that can request human input at inference time, directing human attention to the portions of the videos whose correct annotation would provide the biggest performance improvements. Our primary contribution is to show that by mapping video frames in a camera network onto a graphical model, we can apply collective classification and active inference algorithms to significantly increase the performance of the retrieval system, while minimizing the number of human annotations required.
Keywords: active; annotation; probabilistic; frame; cameras; inference; inference; camera; mechanisms; probability; search; model; human; model; retrieval; network; graphical; problem; video; problems; video; processing; retrieval; video; signal; system; searching

Active inference for retrieval in camera networks - Daozheng Chen; Bilgic,Mustafa; Getoor, Lise; Jacobs, David W.; Mihalkova,Lilyana; Tom Yeh (Person-Oriented Vision (POV), 2011 IEEE Workshop on, 2011)
We address the problem of searching camera network videos to retrieve frames containing specified individuals. We show the benefit of utilizing a learned probabilistic model that captures dependencies among the cameras. In addition, we develop an active inference framework that can request human input at inference time, directing human attention to the portions of the videos whose correct annotation would provide the biggest performance improvements. Our primary contribution is to show that by mapping video frames in a camera network onto a graphical model, we can apply collective classification and active inference algorithms to significantly increase the performance of the retrieval system, while minimizing the number of human annotations required.

Advances in Video-Based Biometrics - Chellapa, Rama; Turaga,P. (Advances in Imaging and Electron Physics, 2011)

Applying graphics processor acceleration in a software defined radio prototyping environment - Plishker,W.; Zaki, G.F.; Bhattacharyya, Shuvra S.; Clancy, C.; Kuykendall, J. (2011 22nd IEEE International Symposium on Rapid System Prototyping (RSP), 2011)
With higher bandwidth requirements and more complex protocols, software defined radio (SDR) has ever growing computational demands. SDR applications have different levels of parallelism that can be exploited on multicore platforms, but design and programming difficulties have inhibited the adoption of specialized multicore platforms like graphics processors (GPUs). In this work we propose a new design flow that augments a popular existing SDR development environment (GNU Radio), with a dataflow foundation and a stand-alone GPU accelerated library. The approach gives an SDR developer the ability to prototype a GPU accelerated application and explore its design space fast and effectively. We demonstrate this design flow on a standard SDR benchmark and show that deciding how to utilize a GPU can be non-trivial for even relatively simple applications.
Keywords: Acceleration; coprocessors; dataflow foundation; GNU radio; Graphics processing unit; graphics processor acceleration; Kernel; Libraries; multicore platforms; Multicore processing; PARALLEL PROCESSING; Pipelines; Protocols; software defined radio prototyping environment; software radio; stand-alone GPU accelerated library

Aquatic Realm and Cholera - Huq,A.; Grim,C. J.; Rita R Colwell (Epidemiological and Molecular Aspects on Cholera, 2011)
Cholera is an ancient disease that can be severe and life threatening. It occurs predominantly in areas of the world where populations lack safe drinking water. Epidemics of cholera are linked with malnutrition, poor sanitation, and conditions resulting from natural disasters such as severe flooding. According to a report published by WHO in 2000 [1], cholera remains a major public health problem and is becoming increasingly important since the number of countries in which cholera is endemic continues to increase. Unfortunately, outbreaks of the disease continue into the twenty-first century with ominous portent in the wake of global climate change [1]. Yet cholera is a preventable disease if people have access to safe drinking water and are properly educated how to protect themselves from the risk of infection with vibrios. Cholera also is an easily treatable disease. Oral rehydration therapy, a solution containing glucose and appropriate salts, has proven to be effective for treatment of most cholera victims [2]. Nevertheless, each year, tens of thousands of people are victims of the disease, bringing this “curse of humankind” to modern civilization. Present understanding of cholera is based on studies conducted over the past three decades and significant new information has been gained concerning environmental factors associated with this disease, especially how to detect the bacterium and where it lives in the natural environment, outside the human gut, and what triggers the annual outbreaks that occur with remarkable regularity. Environmental research on Vibrio cholerae and cholera has provided insights for prediction and prevention of the disease it causes, while the race for effective vaccines against cholera continues.

An assessment of systems and software engineering scholars and institutions (2003–2007 and 2004–2008) - Wong,W. Eric; Tse,T.H.; Glass,Robert L.; Basili, Victor R.; Chen,T.Y. (Journal of Systems and Software, 2011)
An ongoing, annual survey of publications in systems and software engineering identifies the top 15 scholars and institutions in the field over a 5-year period. Each ranking is based on the weighted scores of the number of papers published in TSE, TOSEM, JSS, SPE, EMSE, IST, and Software of the corresponding period. This report summarizes the results for 2003–2007 and 2004–2008. The top-ranked institution is Korea Advanced Institute of Science and Technology, Korea for 2003–2007, and Simula Research Laboratory, Norway for 2004–2008, while Magne Jørgensen is the top-ranked scholar for both periods.
Keywords: Research publications; Systems and software engineering; Top institutions; Top scholars

Associating the visual representation of user interfaces with their internal structures and metadata - Chang,Tsung-Hsiang; Tom Yeh; Miller,Rob (Proceedings of the 24th annual ACM symposium on User interface software and technology, 2011)
Pixel-based methods are emerging as a new and promising way to develop new interaction techniques on top of existing user interfaces. However, in order to maintain platform independence, other available low-level information about GUI widgets, such as accessibility metadata, was neglected intentionally. In this paper, we present a hybrid framework, PAX, which associates the visual representation of user interfaces (i.e. the pixels) and their internal hierarchical metadata (i.e. the content, role, and value). We identify challenges to building such a framework. We also develop and evaluate two new algorithms for detecting text at arbitrary places on the screen, and for segmenting a text image into individual word blobs. Finally, we validate our framework in implementations of three applications. We enhance an existing pixel-based system, Sikuli Script, and preserve the readability of its script code at the same time. Further, we create two novel applications, Screen Search and Screen Copy, to demonstrate how PAX can be applied to development of desktop-level interactive systems.
Keywords: accessibility api; Graphical user interfaces; Pixel; text detection; text segmentation

AVSS 2011 demo session: A large-scale benchmark dataset for event recognition in surveillance video - Oh,Sangmin; Hoogs,Anthony; Perera,Amitha; Cuntoor,Naresh; Chen,Chia-Chih; Lee,Jong Taek; Mukherjee,Saurajit; Aggarwal, JK; Lee,Hyungtae; Davis, Larry S.; Swears,Eran; Wang,Xiaoyang; et al. (Advanced Video and Signal-Based Surveillance (AVSS), 2011 8th IEEE International Conference on, 2011)
We introduce to the surveillance community the VIRAT Video Dataset[1], which is a new large-scale surveillance video dataset designed to assess the performance of event recognition algorithms in realistic scenes1.

Blurring-invariant Riemannian metrics for comparing signals and images - Zhengwu Zhang; Klassen, E.; Srivastava, A.; Turaga,P.; Chellapa, Rama (2011 IEEE International Conference on Computer Vision (ICCV), 2011)
We propose a novel Riemannian framework for comparing signals and images in a manner that is invariant to their levels of blur. This framework uses a log-Fourier representation of signals/images in which the set of all possible Gaussian blurs of a signal, i.e. its orbits under semigroup action of Gaussian blur functions, is a straight line. Using a set of Riemannian metrics under which the group actions are by isometries, the orbits are compared via distances between orbits. We demonstrate this framework using a number of experimental results involving 1D signals and 2D images.
Keywords: blurring-invariant Riemannian metrics; Estimation; Fourier transforms; Gaussian blur function; Gaussian processes; image representation; log-Fourier representation; measurement; Orbits; Polynomials; signal representation; Space vehicles; vectors

Brief announcement: better speedups for parallel max-flow - Caragea,G.C.; Vishkin, Uzi (Proceedings of the 23rd ACM symposium on Parallelism in algorithms and architectures, 2011)
We present a parallel solution to the Maximum-Flow (Max-Flow) problem, suitable for a modern many-core architec- ture. We show that by starting from a PRAM algorithm, following an established “programmer’s workflow” and tar- geting XMT, a PRAM-inspired many-core architecture, we achieve significantly higher speed-ups than previous approaches. Comparison with the fastest known serial max-flow imple- mentation on a modern CPU demonstrates for the first time potential for orders-of-magnitude performance improvement for Max-Flow. Using XMT, the PRAM Max-Flow algorithm is also much easier to program than for other parallel plat- forms, contributing a powerful example toward dual valida- tion of both PRAM algorithmics and XMT.

Broadband internet performance: A view from the gateway - Sundaresan,S.; de Donato,W.; Feamster, Nick; Teixeira,R.; Crawford,S.; Pescapè,A. (SIGCOMM-Computer Communication Review, 2011)
We present the first study of network access link performance mea-sured directly from home gateway devices. Policymakers, ISPs, and users are increasingly interested in studying the performance of Internet access links. Because of many confounding factors in a home network or on end hosts, however, thoroughly understanding access network performance requires deploying measurement in- frastructure in users’ homes as gateway devices. In conjunction with the Federal Communication Commission’s study of broad- band Internet access in the United States, we study the throughput and latency of network access links using longitudinal measure- ments from nearly 4,000 gateway devices across 8 ISPs from a de- ployment of over 4,200 devices. We study the performance users achieve and how various factors ranging from the user’s choice of modem to the ISP’s traffic shaping policies can affect performance. Our study yields many important findings about the characteristics of existing access networks. Our findings also provide insights into the ways that access network performance should be measured and presented to users, which can help inform ongoing broader efforts to benchmark the performance of access networks.

Can Deliberately Incomplete Gene Sample Augmentation Improve a Phylogeny Estimate for the Advanced Moths and Butterflies (Hexapoda: Lepidoptera)? - Cho,Soowon; Zwick,Andreas; Regier,Jerome C; Mitter,Charles; Cummings, Michael P.; Yao,Jianxiu; Du,Zaile; Zhao,Hong; Kawahara,Akito Y; Weller,Susan; Davis,Donald R; Baixeras,Joaquin; et al. (Systematic BiologySyst Biol, 2011)
This paper addresses the question of whether one can economically improve the robustness of a molecular phylogeny estimate by increasing gene sampling in only a subset of taxa, without having the analysis invalidated by artifacts arising from large blocks of missing data. Our case study stems from an ongoing effort to resolve poorly understood deeper relationships in the large clade Ditrysia ( > 150,000 species) of the insect order Lepidoptera (butterflies and moths). Seeking to remedy the overall weak support for deeper divergences in an initial study based on five nuclear genes (6.6 kb) in 123 exemplars, we nearly tripled the total gene sample (to 26 genes, 18.4 kb) but only in a third (41) of the taxa. The resulting partially augmented data matrix (45% intentionally missing data) consistently increased bootstrap support for groupings previously identified in the five-gene (nearly) complete matrix, while introducing no contradictory groupings of the kind that missing data have been predicted to produce. Our results add to growing evidence that data sets differing substantially in gene and taxon sampling can often be safely and profitably combined. The strongest overall support for nodes above the family level came from including all nucleotide changes, while partitioning sites into sets undergoing mostly nonsynonymous versus mostly synonymous change. In contrast, support for the deepest node for which any persuasive molecular evidence has yet emerged (78–85% bootstrap) was weak or nonexistent unless synonymous change was entirely excluded, a result plausibly attributed to compositional heterogeneity. This node (Gelechioidea + Apoditrysia), tentatively proposed by previous authors on the basis of four morphological synapomorphies, is the first major subset of ditrysian superfamilies to receive strong statistical support in any phylogenetic study. A “more-genes-only” data set (41 taxa×26 genes) also gave strong signal for a second deep grouping (Macrolepidoptera) that was obscured, but not strongly contradicted, in more taxon-rich analyses.
Keywords: Ditrysia; gene sampling; Hexapoda; Lepidoptera; missing data; molecular phylogenetics; nuclear genes; taxon sampling

Capacity of wireless networks under SINR interference constraints - Chafekar,Deepti; Anil Kumar,V.; Marathe,Madhav; Parthasarathy,Srinivasan; Srinivasan, Aravind (Wireless Networks, 2011)
A fundamental problem in wireless networks is to estimate their throughput capacity—given a set of wireless nodes and a set of connections, what is the maximum rate at which data can be sent on these connections. Most of the research in this direction has focused either on random distributions of points, or has assumed simple graph-based models for wireless interference. In this paper, we study the capacity estimation problem using a realistic Signal to Interference Plus Noise Ratio (SINR) model for interference, on arbitrary wireless networks without any assumptions on node distributions. The problem becomes much more challenging for this setting, because of the non-locality of the SINR model. Recent work by Moscibroda et al. (IEEE INFOCOM 2006, ACM MobiHoc 2006) has shown that the throughput achieved by using SINR models can differ significantly from that obtained by using graph-based models. In this work, we develop polynomial time algorithms to provably approximate the throughput capacity of wireless network under the SINR model.

Cell cycle dependent TN-C promoter activity determined by live cell imaging. - Halter, Michael; Sisan, Daniel R; Chalfoun, Joe; Stottrup, Benjamin L; Cardone, Antonio; Dima,Alden A.; Tona, Alessandro; Plant,Anne L.; Elliott, John T (Cytometry. Part A : the journal of the International Society for Analytical Cytology, 2011)
The extracellular matrix protein tenascin-C plays a critical role in development, wound healing, and cancer progression, but how it is controlled and how it exerts its physiological responses remain unclear. By quantifying the behavior of live cells with phase contrast and fluorescence microscopy, the dynamic regulation of TN-C promoter activity is examined. We employ an NIH 3T3 cell line stably transfected with the TN-C promoter ligated to the gene sequence for destabilized green fluorescent protein (GFP). Fully automated image analysis routines, validated by comparison with data derived from manual segmentation and tracking of single cells, are used to quantify changes in the cellular GFP in hundreds of individual cells throughout their cell cycle during live cell imaging experiments lasting 62 h. We find that individual cells vary substantially in their expression patterns over the cell cycle, but that on average TN-C promoter activity increases during the last 40% of the cell cycle. We also find that the increase in promoter activity is proportional to the activity earlier in the cell cycle. This work illustrates the application of live cell microscopy and automated image analysis of a promoter-driven GFP reporter cell line to identify subtle gene regulatory mechanisms that are difficult to uncover using population averaged measurements.
Keywords: Animals; cell cycle; Gene Expression Regulation; Green Fluorescent Proteins; Image Processing, Computer-Assisted; Mice; Microscopy, Fluorescence; Microscopy, Phase-Contrast; NIH 3T3 Cells; Promoter Regions, Genetic; Tenascin

Characterizing Attackers and Attacks: An Empirical Study - Salles-Loustau,G.; Berthier,R.; Collange,E.; Sobesto,B.; Michel Cukier (2011)
This paper describes an empirical research study to characterize attackers and attacks against targets of opportunity. A honey net infrastructure was built and deployed over 167 days that leveraged three different honey pot configurations and a SSH-based authentication proxy to attract and follow attackers over several weeks. A total of 211 attack sessions were recorded and evidence was collected at each stage of the attack sequence: from discovery to intrusion and exploitation of rogue software. This study makes two important contributions: 1) we introduce a new approach to measure attacker skills, and 2) we leverage keystroke profile analysis to differentiate attackers beyond their IP address of origin.
Keywords: attack sessions; attacker characterization; attacker skill measurement; honey net infrastructure; honey pot configurations; IP address; keystroke profile analysis; opportunity target; rogue software exploitation; security of data; SSH-based authentication proxy

Clonal transmission, dual peak, and off-season cholera in Bangladesh - Alam,M.; Islam,A.; Bhuiyan,N. A.; Rahim,N.; Hossain,A.; Khan,G. Y.; Ahmed,D.; Watanabe,H.; Izumiya,H.; Faruque,A. S. G.; Rita R Colwell (Infection Ecology & Epidemiology, 2011)
Vibrio cholerae is an estuarine bacterium associated with a single peak of cholera (March–May) in coastal villages of Bangladesh. For an unknown reason, however, cholera occurs in a unique dual peak (March–May and September–November) pattern in the city of Dhaka that is bordered by a heavily polluted freshwater river system and flood embankment. In August 2007, extreme flooding was accompanied by an unusually severe diarrhea outbreak in Dhaka that resulted in a record high illness. This study was aimed to understand the unusual outbreak and if it was related to the circulation of a new V. cholerae clone. Nineteen V. cholerae isolated during the peak of the 2007 outbreak were subjected to extensive phenotypic and molecular analyses, including multi-locus genetic screening by polymerase chain reaction (PCR), sequence-typing of the ctxB gene, and pulsed-field gel electrophoresis (PFGE). Factors associated with the unusual incidence of cholera were determined and analysis of the disease severity was done. Overall, microbiological and molecular data confirmed that the hypervirulent V. cholerae was O1 biotype El Tor (ET) that possessed cholera toxin (CT) of the classical biotype. The PFGE (NotI) and dendrogram clustering confirmed that the strains were clonal and related to the pre-2007 variant ET from Dhaka and Matlab and resembled one of two distinct clones of the variant ET confirmed to be present in the estuarine ecosystem of Bangladesh. Results of the analyses of both diarrheal case data for three consecutive years (2006–2008) and regional hydroclimatology over three decades (1980–2009) clearly indicate that the pattern of cholera occurring in Dhaka, and not seen at other endemic sites, was associated with flood waters transmitting the infectious clone circulating via the fecal-oral route during and between the dual seasonal cholera peaks in Dhaka. Circular river systems and flood embankment likely facilitate transmission of infectious V. cholerae throughout the year that leads to both sudden and off-season outbreaks in the densely populated urban ecosystem of Dhaka. Clonal recycling of hybrid El Tor with increasing virulence in a changing climate and in a region with a growing urban population represents a serious public health concern for Bangladesh.

Communicating with Caps: Managing Usage Caps in Home Networks - Kim, Hyojoon; Sundaresan, Srikanth; Marshini Chetty; Feamster, Nick; Edwards, W. Keith (SIGCOMM Comput. Commun. Rev., 2011)
As Internet service providers increasingly implement and impose "usage caps", consumers need better ways to help them understand and control how devices in the home use up the available network resources or available capacity. Towards this goal, we will demonstrate a system that allows users to monitor and manage their usage caps. The system uses the BISMark firmware running on network gateways to collect usage statistics and report them to a logically centralized controller, which displays usage information. The controller allows users to specify policies about how different people, devices, and applications should consume the usage cap; it implements and enforces these policies via a secure OpenFlow control channel to each gateway device. The demonstration will show various use cases, such as limiting the usage of a particular application, visualizing usage statistics, and allowing users within a single household to "trade" caps with one another.
Keywords: home network; openflow; usage cap

Communicating with caps: managing usage caps in home networks - Kim,Hyojoon; Sundaresan,Srikanth; Marshini Chetty; Feamster, Nick; Edwards,W. Keith (ACM SIGCOMM Computer Communication Review, 2011)
As Internet service providers increasingly implement and impose "usage caps", consumers need better ways to help them understand and control how devices in the home use up the available network resources or available capacity. Towards this goal, we will demonstrate a system that allows users to monitor and manage their usage caps. The system uses the BISMark firmware running on network gateways to collect usage statistics and report them to a logically centralized controller, which displays usage information. The controller allows users to specify policies about how different people, devices, and applications should consume the usage cap; it implements and enforces these policies via a secure OpenFlow control channel to each gateway device. The demonstration will show various use cases, such as limiting the usage of a particular application, visualizing usage statistics, and allowing users within a single household to "trade" caps with one another.
Keywords: home network; openflow; usage cap

Component-based restoration of speckled images - Patel, Vishal M.; Easley,G. R; Chellapa, Rama (2011 18th IEEE International Conference on Image Processing (ICIP), 2011)
Many coherent imaging modalities are often characterized by a multiplicative noise, known as speckle which often makes the interpretation of data difficult. In this paper, we present a speckle reduction algorithm based on separating the structure and texture components of SAR images. An iterative algorithm based on surrogate functionals is presented that solves the component optimization formulation. Experiments indicate this proposed method performs favorably compared to state-of-the-art speckle reduction methods.
Keywords: coherent imaging modalities; component optimization formulation; component-based restoration; Dictionaries; image restoration; iterative algorithm; iterative methods; multiplicative noise; NOISE; optimisation; radar imaging; SAR images; Speckle; speckle reduction algorithm; speckled images; structure components; surrogate functionals; synthetic aperture radar; texture components; transforms; TV

A computational statistics approach for estimating the spatial range of morphogen gradients - Kanodia, Jitendra S.; Kim, Yoosik; Tomer, Raju; Zia Khan; Chung, Kwanghun; Storey, John D.; Lu, Hang; Keller, Philipp J.; Shvartsman, Stanislav Y. (Development, 2011)
A crucial issue in studies of morphogen gradients relates to their range: the distance over which they can act as direct regulators of cell signaling, gene expression and cell differentiation. To address this, we present a straightforward statistical framework that can be used in multiple developmental systems. We illustrate the developed approach by providing a point estimate and confidence interval for the spatial range of the graded distribution of nuclear Dorsal, a transcription factor that controls the dorsoventral pattern of the Drosophila embryo.
Keywords: Computational Biology; Confidence interval; Dorsal gradient; Drosophila embryo; Morphogen gradient; Statistics

Computing the Tree of Life: Leveraging the Power of Desktop and Service Grids - Bazinet,A. L; Cummings, Michael P. (Parallel and Distributed Processing Workshops and Phd Forum (IPDPSW), 2011 IEEE International Symposium on, 2011)
The trend in life sciences research, particularly in molecular evolutionary systematics, is toward larger data sets and ever-more detailed evolutionary models, which can generate substantial computational loads. Over the past several years we have developed a grid computing system aimed at providing researchers the computational power needed to complete such analyses in a timely manner. Our grid system, known as The Lattice Project, was the first to combine two models of grid computing - the service model, which mainly federates large institutional HPC resources, and the desktop model, which harnesses the power of PCs volunteered by the general public. Recently we have developed a "science portal" style web interface that makes it easier than ever for phylogenetic analyses to be completed using GARLI, a popular program that uses a maximum likelihood method to infer the evolutionary history of organisms on the basis of genetic sequence data. This paper describes our approach to scheduling thousands of GARLI jobs with diverse requirements to heterogeneous grid resources, which include volunteer computers running BOINC software. A key component of this system provides a priori GARLI runtime estimates using machine learning with random forests.
Keywords: (artificial; (mathematics); user; analysis; science; BOINC; computation; grid; computational; computing; computing; information; computing; machine; data; grid; estimation; portals; trees; evolutionary; Grid; grids; service; handling; evolutionary; history; evolutionary; intelligence); maximum; interface; computational; interfaces; jobs; HPC; learning; maximum; likelihood; load; Internet; data; method; molecular; model; genetic; model; substantial; portal; service; power; data; project; life; resource; lattice; resource; Web; sequence; services; learning; sets; evolutionary; software; GARLI; system; heterogeneous; systematics; phylogenetic; tree

Creating contextual help for GUIs using screenshots - Tom Yeh; Chang,Tsung-Hsiang; Xie,Bo; Walsh,Greg; Watkins,Ivan; Wongsuphasawat,Krist; Huang,Man; Davis, Larry S.; Bederson, Benjamin B. (Proceedings of the 24th annual ACM symposium on User interface software and technology, 2011)
Contextual help is effective for learning how to use GUIs by showing instructions and highlights on the actual interface rather than in a separate viewer. However, end-users and third-party tech support typically cannot create contextual help to assist other users because it requires programming skill and source code access. We present a creation tool for contextual help that allows users to apply common computer skills-taking screenshots and writing simple scripts. We perform pixel analysis on screenshots to make this tool applicable to a wide range of applications and platforms without source code access. We evaluated the tool's usability with three groups of participants: developers, in-structors, and tech support. We further validated the applicability of our tool with 60 real tasks supported by the tech support of a university campus.
Keywords: contextual help; help; pixel analysis

A Decomposition-based Approach to Modeling and Understanding Arbitrary Shapes - Canino,D.; De Floriani, Leila (Eurographics Italian Chapter Conference 2011, 2011)

Design methods for Wireless Sensor Network Building Energy Monitoring Systems - Cho, Inkeun; Chung-Ching Shen; Potbhare, S.; Bhattacharyya, Shuvra S.; Goldsman,N. (2011 IEEE 36th Conference on Local Computer Networks (LCN), 2011)
In this paper, we present a new energy analysis method for evaluating energy consumption of embedded sensor nodes at the application level and the network level. Then we apply the proposed energy analysis method to develop new energy management schemes in order to maximize lifetime for Wireless Sensor Network Building Energy Monitoring Systems (WSNBEMS). At the application level, we develop a new design approach that uses dataflow techniques to model the application-level interfacing behavior between the processor and sensors on an embedded sensor node. At the network level, we analyze the energy consumption of the IEEE 802.15.4 MAC functionality. Based on our techniques for modeling and energy analysis, we have implemented an optimized WSNBEMS for a real building, and validated our energy analysis techniques through measurements on this implementation. The performance of our implementation is also evaluated in terms of monitoring accuracy and energy consumption savings. We have demonstrated that by applying the proposed scheme, system lifetime can be improved significantly without affecting monitoring accuracy.
Keywords: Analytical models; application-level interfacing behavior; building energy monitoring system; Buildings; dataflow technique; embedded sensor node; energy analysis method; Energy consumption; energy management systems; Energy resolution; IEEE 802.15.4 MAC functionality; Monitoring; OPTIMIZATION; wireless sensor network; Wireless sensor networks; WSNBEMS; Zigbee

Designing Optimal Spectral Filters for Inverse Problems - Chung,Julianne M.; Chung,Matthias; O'Leary, Dianne P. (SIAM Journal on Scientific Computing, 2011)

Dimension-independent simplification and refinement of Morse complexes - Čomić,Lidija; De Floriani, Leila (Graphical Models, 2011)
Ascending and descending Morse complexes, determined by a scalar field f defined over a manifold M, induce a subdivision of M into regions associated with critical points of f, and compactly represent the topology of M. We define two simplification operators on Morse complexes, which work in arbitrary dimensions, and we define their inverse refinement operators. We describe how simplification and refinement operators affect Morse complexes on M, and we show that these operators form a complete set of atomic operators to create and update Morse complexes on M. Thus, any operator that modifies Morse complexes on M can be expressed as a suitable sequence of the atomic simplification and refinement operators we have defined. The simplification and refinement operators also provide a suitable basis for the construction of a multi-resolution representation of Morse complexes.
Keywords: Morse complexes; Morse theory; Refinement; shape modeling; simplification; Topological representations

Direct targeting of Sec23a by miR-200s influences cancer cell secretome and promotes metastatic colonization - Korpal, Manav; Ell, Brian J.; Buffa, Francesca M.; Ibrahim, Toni; Blanco, Mario A.; Celià-Terrassa, Toni; Mercatali, Laura; Zia Khan; Goodarzi, Hani; Hua, Yuling; Wei, Yong; Hu, Guohong; et al. (Nature Medicine, 2011)
Although the role of miR-200s in regulating E-cadherin expression and epithelial-to-mesenchymal transition is well established, their influence on metastatic colonization remains controversial. Here we have used clinical and experimental models of breast cancer metastasis to discover a pro-metastatic role of miR-200s that goes beyond their regulation of E-cadherin and epithelial phenotype. Overexpression of miR-200s is associated with increased risk of metastasis in breast cancer and promotes metastatic colonization in mouse models, phenotypes that cannot be recapitulated by E-cadherin expression alone. Genomic and proteomic analyses revealed global shifts in gene expression upon miR-200 overexpression toward that of highly metastatic cells. miR-200s promote metastatic colonization partly through direct targeting of Sec23a, which mediates secretion of metastasis-suppressive proteins, including Igfbp4 and Tinagl1, as validated by functional and clinical correlation studies. Overall, these findings suggest a pleiotropic role of miR-200s in promoting metastatic colonization by influencing E-cadherin–dependent epithelial traits and Sec23a-mediated tumor cell secretome.View full text

Disaggregated End-Use Energy Sensing for the Smart Grid - Jon Froehlich; Larson,E.; Gupta,S.; Cohn,G.; Reynolds,M.; Patel,S. (IEEE Pervasive Computing, 2011)
This article surveys existing and emerging disaggregation techniques for energy-consumption data and highlights signal features that might be used to sense disaggregated data in an easily installed and cost-effective manner.
Keywords: Calibration; disaggregated end-use energy sensing; Disaggregated energy sensing; disaggregation data techniques; Electricity; Energy consumption; Energy efficiency; energy-consumption data; Gas; Home appliances; Sensors; Smart grid; Smart grids; smart power grids; Sustainability; Water

Distributed Sensing and Processing for Multi-Camera Networks - Sankaranarayanan,Aswin C.; Chellapa, Rama; Baraniuk,Richard G. (Distributed Video Sensor NetworksDistributed Video Sensor Networks, 2011)
Sensor networks with large numbers of cameras are becoming increasingly prevalent in a wide range of applications, including video conferencing, motion capture, surveillance, and clinical diagnostics. In this chapter, we identify some of the fundamental challenges in designing such systems: robust statistical inference, computationally efficiency, and opportunistic and parsimonious sensing. We show that the geometric constraints induced by the imaging process are extremely useful for identifying and designing optimal estimators for object detection and tracking tasks. We also derive pipelined and parallelized implementations of popular tools used for statistical inference in non-linear systems, of which multi-camera systems are examples. Finally, we highlight the use of the emerging theory of compressive sensing in reducing the amount of data sensed and communicated by a camera network.

A Dive into Online Community Properties - Wagstrom, Patrick; Martino, Jacquelyn; von Kaenel, Juerg; Marshini Chetty; Thomas, John; Jones, Lauretta (CSCW '11, 2011)
As digital communities grow in size their feature sets also grow with them. Different users have different experiences with the same tools and communities. Enterprises and other organizations seeking to leverage these communities need a straightforward way to analyze and compare a variety of salient attributes of these communities. We describe a taxonomy and tool for crowd-sourcing user based evaluations of enterprise relevant attributes of digital communities and present the results of a small scale study on its usefulness and stability across multiple raters.
Keywords: enterprise; Online communities; Taxonomy; Visualization

Domain adaptation for object recognition: An unsupervised approach - Gopalan,R.; Ruonan Li; Chellapa, Rama (2011 IEEE International Conference on Computer Vision (ICCV), 2011)
Adapting the classifier trained on a source domain to recognize instances from a new target domain is an important problem that is receiving recent attention. In this paper, we present one of the first studies on unsupervised domain adaptation in the context of object recognition, where we have labeled data only from the source domain (and therefore do not have correspondences between object categories across domains). Motivated by incremental learning, we create intermediate representations of data between the two domains by viewing the generative subspaces (of same dimension) created from these domains as points on the Grassmann manifold, and sampling points along the geodesic between them to obtain subspaces that provide a meaningful description of the underlying domain shift. We then obtain the projections of labeled source domain data onto these subspaces, from which a discriminative classifier is learnt to classify projected data from the target domain. We discuss extensions of our approach for semi-supervised adaptation, and for cases with multiple source and target domains, and report competitive results on standard datasets.
Keywords: Data models; data representations; discriminative classifier; Feature extraction; Grassmann manifold; image sampling; incremental learning; labeled source domain; Manifolds; measurement; object category; Object recognition; Principal component analysis; sampling points; semisupervised adaptation; target domain; underlying domain shift; unsupervised approach; unsupervised domain adaptation; Unsupervised learning; vectors

The DSPCAD Lightweight Dataflow Environment: Introduction to LIDE Version 0.1 - Chung-Ching Shen; Wang, Lai-Huei; Cho, Inkeun; Kim, Scott; Won, Stephen; Plishker,William; Bhattacharyya, Shuvra S. (Technical Reports from UMIACS, 2011)
LIDE (the DSPCAD Lightweight Dataflow Environment) is a flexible,lightweight design environment that allows designers to experiment with dataflow-based approaches for design and implementation of digital signal processing (DSP) systems. LIDE contains libraries of dataflow graph elements (primitive actors, hierarchical actors, and edges) and utilities that assist designers in modeling, simulating, and implementing DSP systems using formal dataflow techniques. The libraries of dataflow graph elements (mainly actors) contained in LIDE provide useful building blocks that can be used to construct signal processing applications, and that can be used as examples that designers can adapt to create their own, customized LIDE actors. Furthermore, by using LIDE along with the DSPCAD Integrative Command Line Environment (DICE), designers can efficiently create and execute unit tests for user-designed actors. This report provides an introduction to LIDE. The report includes details on the process for setting up the LIDE environment, and covers methods for using pre-designed libraries of graph elements, as well as creating user-designed libraries and associated utilities using the C language. The report also gives an introduction to the C language plug-in for dicelang. This plug-in, called dicelang-C, provides features for efficient C-based project development and maintenance that are useful to apply when working with LIDE.
Keywords: Technical Report

Dynamic inference of static types for ruby - An,Jong-hoon (David); Chaudhuri,Avik; Foster, Jeffrey S.; Hicks, Michael W. (Proceedings of the 38th annual ACM SIGPLAN-SIGACT symposium on Principles of programming languages, 2011)
There have been several efforts to bring static type inference to object-oriented dynamic languages such as Ruby, Python, and Perl. In our experience, however, such type inference systems are extremely difficult to develop, because dynamic languages are typically complex, poorly specified, and include features, such as eval and reflection, that are hard to analyze. In this paper, we introduce constraint-based dynamic type inference, a technique that infers static types based on dynamic program executions. In our approach, we wrap each run-time value to associate it with a type variable, and the wrapper generates constraints on this type variable when the wrapped value is used. This technique avoids many of the often overly conservative approximations of static tools, as constraints are generated based on how values are used during actual program runs. Using wrappers is also easy to implement, since we need only write a constraint resolution algorithm and a transformation to introduce the wrappers. The best part is that we can eat our cake, too: our algorithm will infer sound types as long as it observes every path through each method body---note that the number of such paths may be dramatically smaller than the number of paths through the program as a whole. We have developed Rubydust, an implementation of our algorithm for Ruby. Rubydust takes advantage of Ruby's dynamic features to implement wrappers as a language library. We applied Rubydust to a number of small programs and found it to be both easy to use and useful: Rubydust discovered 1 real type error, and all other inferred types were correct and readable.
Keywords: dynamic languages; dynamic type inference; ruby; static types

Dynamic Processing Allocation in Video - Daozheng Chen; Bilgic,M.; Getoor, Lise; Jacobs, David W. (Pattern Analysis and Machine Intelligence, IEEE Transactions on, 2011)
Large stores of digital video pose severe computational challenges to existing video analysis algorithms. In applying these algorithms, users must often trade off processing speed for accuracy, as many sophisticated and effective algorithms require large computational resources that make it impractical to apply them throughout long videos. One can save considerable effort by applying these expensive algorithms sparingly, directing their application using the results of more limited processing. We show how to do this for retrospective video analysis by modeling a video using a chain graphical model and performing inference both to analyze the video and to direct processing. We apply our method to problems in background subtraction and face detection, and show in experiments that this leads to significant improvements over baseline algorithms.
Keywords: algorithms; digital; allocation; video; analysis; computer; background; detection; graphical; detection; resource; graphics; face; model; resource; processing; processing; face; recognition; object; signal; subtraction; baseline; video

Empirical Studies in Information Visualization: Seven Scenarios - Lam,H.; Bertini,E.; Isenberg,P.; Plaisant, Catherine; Carpendale,S. (Visualization and Computer Graphics, IEEE Transactions on, 2011)
We take a new, scenario based look at evaluation in information visualization. Our seven scenarios, evaluating visual data analysis and reasoning, evaluating user performance, evaluating user experience, evaluating environments and work practices, evaluating communication through visualization, evaluating visualization algorithms, and evaluating collaborative data analysis were derived through an extensive literature review of over 800 visualization publications. These scenarios distinguish different study goals and types of research questions and are illustrated through example studies. Through this broad survey and the distillation of these scenarios we make two contributions. One, we encapsulate the current practices in the information visualization research community and, two, we provide a different approach to reaching decisions about what might be the most effective evaluation of a given information visualization. Scenarios can be used to choose appropriate research questions and goals and the provided examples can be consulted for guidance on how to design one's own study.

Entropy rate superpixel segmentation - Ming-Yu Liu; Tuzel, O.; Ramalingam, S.; Chellapa, Rama (2011 IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2011)
We propose a new objective function for superpixel segmentation. This objective function consists of two components: entropy rate of a random walk on a graph and a balancing term. The entropy rate favors formation of compact and homogeneous clusters, while the balancing function encourages clusters with similar sizes. We present a novel graph construction for images and show that this construction induces a matroid - a combinatorial structure that generalizes the concept of linear independence in vector spaces. The segmentation is then given by the graph topology that maximizes the objective function under the matroid constraint. By exploiting submodular and mono-tonic properties of the objective function, we develop an efficient greedy algorithm. Furthermore, we prove an approximation bound of ½ for the optimality of the solution. Extensive experiments on the Berkeley segmentation benchmark show that the proposed algorithm outperforms the state of the art in all the standard evaluation metrics.
Keywords: balancing function; Berkeley segmentation benchmark; Complexity theory; Entropy; entropy rate; graph construction; graph theory; graph topology; greedy algorithm; Greedy algorithms; homogeneous clusters; Image edge detection; Image segmentation; matrix algebra; matroid constraint; measurement; pattern clustering; Random variables; standard evaluation metrics; superpixel segmentation; vector spaces

ON THE ESTIMATION OF 3D HUMAN BODY MODELS AND POSE FROM MULTIPLE CAMERAS - Sundaresan, A.; Chellapa, Rama (EMERGING TOPICS IN COMPUTER VISION AND ITS APPLICATIONS, 2011)
We present a completely automatic algorithm for initializing and tracking the articulated motion of humans using image sequences obtained from multiple cameras. We discuss the challenges in solving this problem and compare our work to some of the state of the art techniques today. We use a detailed articulated human body model composed of sixteen rigid segments that allows both translation and rotation at joints. Voxel data of the subject obtained from the images is segmented into the different articulated chains using Laplacian Eigenmaps. The segmented chains are registered in a subset of the frames using a single-frame registration technique and subsequently used to initialize the pose in the sequence. A temporal registration method is then used to identify the partially segmented or unregistered articulated chains in the remaining frames in the sequence. The tracker uses motion cues such as pixel displacement as well as 2D and 3D shape cues such as silhouettes, motion residues and skeleton curves. The use of complementary cues in the tracking algorithm alleviates the twin problems of drift and convergence to incorrect solutions. The use of multiple cameras also allows us to deal with the problems due to self-occlusion and kinematic singularity. We present tracking results on sequences with different kinds of motion to illustrate the effectiveness of our approach.

The evolution of stochastic grammars for representation and recognition of activities in videos - Chellapa, Rama (2011 IEEE International Conference on Computer Vision Workshops (ICCV Workshops), 2011)
The speaker is one of the privileged many to have been taught syntactic pattern recognition methods by the Late Prof. K.S. Fu. In this talk, I will discuss the evolution of stochastic image grammars from the early seventies to now with a focus on image and video understanding applications.
Keywords: activity recognition; activity representation; Conferences; Educational institutions; Grammar; Image analysis; image recognition; image representation; image understanding; pattern recognition; stochastic image grammars; syntactic pattern recognition methods; video signal processing; video understanding; Videos

Example-Driven Manifold Priors for Image Deconvolution - Ni,Jie; Turaga,P.; Patel, Vishal M.; Chellapa, Rama (Image Processing, IEEE Transactions on, 2011)
Image restoration methods that exploit prior information about images to be estimated have been extensively studied, typically using the Bayesian framework. In this paper, we consider the role of prior knowledge of the object class in the form of a patch manifold to address the deconvolution problem. Specifically, we incorporate unlabeled image data of the object class, say natural images, in the form of a patch-manifold prior for the object class. The manifold prior is implicitly estimated from the given unlabeled data. We show how the patch-manifold prior effectively exploits the available sample class data for regularizing the deblurring problem. Furthermore, we derive a generalized cross-validation (GCV) function to automatically determine the regularization parameter at each iteration without explicitly knowing the noise variance. Extensive experiments show that this method performs better than many competitive image deconvolution methods.
Keywords: Bayesian; cross-validation; data; Bayes; deconvolution; image; determination; deblurring; estimation; framework; GCV; function; automatic; function; image; image; image; patch-manifold; manifold; method; iteration; method; natural; methods; deconvolution; image; methods; natural; parameter; prior; generalized; prior; unlabeled; problem; regularization; regularization; example-driven; restoration; restoration; iterative; scenes; parameter

Exploring compression effects for improved source camera identification using strongly compressed video - Chuang,Wei-Hong; Su,Hui; M. Wu (Image Processing (ICIP), 2011 18th IEEE International Conference on, 2011)
This paper presents a study of the video compression effect on source camera identification based on the Photo-Response Non-Uniformity (PRNU). Specifically, the reliability of different types of frames in a compressed video is first investigated, which shows quantitatively that I-frames are more reliable than P-frames for PRNU estimation. Motivated by this observation, a new mechanism for estimating the reference PRNU and two mechanisms for estimating the test-video PRNU are proposed to achieve higher accuracy with fewer frames used. Experiments are performed to validate the effectiveness of the proposed mechanisms.
Keywords: camera; cameras; video; coding; compression; computer; compression; video; estimation; photoresponse; forensics; data; identification; video; non-uniformity; reliability; source; PRNU

Face Detection - Gopalan,Raghuraman; Schwartz,William R.; Chellapa, Rama; Srivastava,Ankur (Visual Analysis of HumansVisual Analysis of Humans, 2011)
Face detection in still images and videos has been extensively studied over the last two decades. Attributed to the recent proliferation of cameras in consumer applications, research in face detection has gradually transformed into more unconstrained settings, with the goal of achieving performance close to humans. This presents two main challenges: (i) in addition to modeling the facial characteristics, understanding the information portrayed by the surrounding scene is important in resolving visual ambiguities, and (ii) the computational time needed for decision making should be compatible for real-time applications, since detection is primarily a front-end process on which additional knowledge extraction is built upon. This chapter begins with a review of recent work in modeling face-specific information, including appearance-based methods used by sliding window classifiers, concepts from learning and local interest-point descriptors, and then focuses on representing the contextual information shared by faces with the surrounding scene. To provide better understanding of working concepts, we discuss a method for learning the semantic context shared by the face with other human body parts that facilitates reasoning under occlusion, and then present an image representation which efficiently encodes contour information to enable fast detection of faces. We conclude the chapter by discussing some existing challenges.

Face Tracking and Recognition in Video - Chellapa, Rama; Du,Ming; Turaga,Pavan; Zhou,Shaohua Kevin (Handbook of Face RecognitionHandbook of Face Recognition, 2011)
In this chapter, we describe the utility of videos in enhancing performance of image-based recognition tasks. We discuss a joint tracking-recognition framework that allows for using the motion information in a video to better localize and identify the person in the video using still galleries. We discuss how to jointly capture facial appearance and dynamics to obtain a parametric representation for video-to-video recognition. We discuss recognition in multi-camera networks where the probe and gallery both consist of multi-camera videos. Concluding remarks and directions for future research are provided.

Face tracking in low resolution videos under illumination variations - Zou, W.W.W.; Chellapa, Rama; Yuen, P.C. (2011 18th IEEE International Conference on Image Processing (ICIP), 2011)
In practical face tracking applications, the face region is often small and affected by illumination variations. We address this problem by using a new feature, namely the Gradient-Logarithmic Field (GLF) feature, in the particle filter framework. The GLF feature is robust under illumination variations and the GLF-based tracker does not assume any model for the face being tracked and is effective in low-resolution video. Experimental results show that the proposed GFL-based tracker works well under significant illumination changes and outperforms some of the state-of-the-art algorithms.
Keywords: Adaptation models; Computational modeling; Face; face recognition; face tracking; GLF-based tracker; gradient methods; gradient-logarithmic field feature; illumination variations; lighting; low resolution videos; low-resolution; particle filter; particle filter framework; particle filtering (numerical methods); Robustness; tracking; video signal processing; Videos; Visual face tracking

A Fast Bilinear Structure from Motion Algorithm Using a Video Sequence and Inertial Sensors - Ramachandran, M.; Veeraraghavan,A.; Chellapa, Rama (IEEE Transactions on Pattern Analysis and Machine Intelligence, 2011)
In this paper, we study the benefits of the availability of a specific form of additional information-the vertical direction (gravity) and the height of the camera, both of which can be conveniently measured using inertial sensors and a monocular video sequence for 3D urban modeling. We show that in the presence of this information, the SfM equations can be rewritten in a bilinear form. This allows us to derive a fast, robust, and scalable SfM algorithm for large scale applications. The SfM algorithm developed in this paper is experimentally demonstrated to have favorable properties compared to the sparse bundle adjustment algorithm. We provide experimental evidence indicating that the proposed algorithm converges in many cases to solutions with lower error than state-of-art implementations of bundle adjustment. We also demonstrate that for the case of large reconstruction problems, the proposed algorithm takes lesser time to reach its solution compared to bundle adjustment. We also present SfM results using our algorithm on the Google StreetView research data set.
Keywords: 3D urban modeling; algorithms; Artificial intelligence; CAMERAS; computer vision.; Convergence; fast bilinear structure; Google StreetView research data set; Image Interpretation, Computer-Assisted; Image reconstruction; Image sensors; Image sequences; Imaging, Three-Dimensional; inertial sensors; Information Storage and Retrieval; Linear systems; minimization; MOTION; motion algorithm; Motion estimation; multiple view geometry; Pattern Recognition, Automated; Sensors; SfM equations; sparse bundle adjustment algorithm; structure from motion; Three dimensional displays; vertical direction; Video Recording; video sequence; video signal processing

From slacktivism to activism: participatory culture in the age of social media - Rotman,Dana; Vieweg,Sarah; Yardi,Sarita; Chi,Ed; Preece,Jenny; Shneiderman, Ben; Pirolli,Peter; Glaisyer,Tom (Proceedings of the 2011 annual conference extended abstracts on Human factors in computing systems, 2011)
Social networking sites (e.g. Facebook), microblogging services (e.g. Twitter), and content-sharing sites (e.g. YouTube and Flickr) have introduced the opportunity for wide-scale, online social participation. Visibility of national and international priorities such as public health, political unrest, disaster relief, and climate change has increased, yet we know little about the benefits - and possible costs - of engaging in social activism via social media. These powerful social issues introduce a need for scientific research into technology mediated social participation. What are the actual, tangible benefits of "greening" Twitter profile pictures in support of the Iranian elections? Does cartooning a Facebook profile picture really raise awareness of child abuse? Are there unintended negative effects through low-risk, low-cost technology-mediated participation? And, is there a difference - in both outcome and engagement level - between different types of online social activism? This SIG will investigate technology mediated social participation through a critical lens, discussing both the potential positive and negative outcomes of such participation. Approaches to designing for increased participation, evaluating effects of participation, and next steps in scientific research directions will be discussed.
Keywords: activism; change; design; participation; slacktivism; social media

Gene Coexpression Network Topology of Cardiac Development, Hypertrophy, and FailureClinical Perspective - Dewey,Frederick E; Perez,Marco V; Wheeler,Matthew T; Watt,Clifton; Spin,Joshua; Langfelder,Peter; Horvath,Steve; Hannenhalli, Sridhar; Cappola,Thomas P.; Ashley,Euan A (Circulation: Cardiovascular GeneticsCirc Cardiovasc Genet, 2011)
Background— Network analysis techniques allow a more accurate reflection of underlying systems biology to be realized than traditional unidimensional molecular biology approaches. Using gene coexpression network analysis, we define the gene expression network topology of cardiac hypertrophy and failure and the extent of recapitulation of fetal gene expression programs in failing and hypertrophied adult myocardium.Methods and Results— We assembled all myocardial transcript data in the Gene Expression Omnibus (n=1617). Because hierarchical analysis revealed species had primacy over disease clustering, we focused this analysis on the most complete (murine) dataset (n=478). Using gene coexpression network analysis, we derived functional modules, regulatory mediators, and higher-order topological relationships between genes and identified 50 gene coexpression modules in developing myocardium that were not present in normal adult tissue. We found that known gene expression markers of myocardial adaptation were members of upregulated modules but not hub genes. We identified ZIC2 as a novel transcription factor associated with coexpression modules common to developing and failing myocardium. Of 50 fetal gene coexpression modules, 3 (6%) were reproduced in hypertrophied myocardium and 7 (14%) were reproduced in failing myocardium. One fetal module was common to both failing and hypertrophied myocardium. Conclusions— Network modeling allows systems analysis of cardiovascular development and disease. Although we did not find evidence for a global coordinated program of fetal gene expression in adult myocardial adaptation, our analysis revealed specific gene expression modules active during both development and disease and specific candidates for their regulation.
Keywords: fetal; Gene expression; heart failure; hypertrophy; myocardium

Graph Analytics-Lessons Learned and Challenges Ahead - Wong,Pak Chung; Chen,Chaomei; Gorg,Carsten; Shneiderman, Ben; Stasko,John; Thomas,Jim (IEEE Computer Graphics and Applications, 2011)
Graph analytics is one of the most influential and important R&D topics in the visual analytics community. Researchers with diverse backgrounds from information visualization, human-computer interaction, computer graphics, graph drawing, and data mining have pursued graph analytics from scientific, technical, and social approaches. These studies have addressed both distinct and common challenges. Past successes and mistakes can provide valuable lessons for revising the research agenda. In this article, six researchers from four academic and research institutes identify graph analytics' fundamental challenges and present both insightful lessons learned from their experience and good practices in graph analytics research. The goal is to critically assess those lessons and shed light on how they can stimulate research and draw attention to grand challenges for graph analytics. The article also establishes principles that could lead to measurable standards and criteria for research.
Keywords: citation analysis; citespace; Computer Graphics; document analysis; graphics and multimedia; greengrid; jigsaw system; modeling; power grid analysis; semantic substrates; simulation; social networks; text analysis; Visualization

GUI Interaction Testing: Incorporating Event Context - Xun Yuan; Cohen,M. B; Memon, Atif M. (Software Engineering, IEEE Transactions on, 2011)
Graphical user interfaces (GUIs), due to their event-driven nature, present an enormous and potentially unbounded way for users to interact with software. During testing, it is important to #x201C;adequately cover #x201D; this interaction space. In this paper, we develop a new family of coverage criteria for GUI testing grounded in combinatorial interaction testing. The key motivation of using combinatorial techniques is that they enable us to incorporate #x201C;context #x201D; into the criteria in terms of event combinations, sequence length, and by including all possible positions for each event. Our new criteria range in both efficiency (measured by the size of the test suite) and effectiveness (the ability of the test suites to detect faults). In a case study on eight applications, we automatically generate test cases and systematically explore the impact of context, as captured by our new criteria. Our study shows that by increasing the event combinations tested and by controlling the relative positions of events defined by the new criteria, we can detect a large number of faults that were undetectable by earlier techniques.
Keywords: automatic test case generation; automatic test pattern generation; combinatorial interaction testing; event driven nature; graphical user interface; Graphical user interfaces; GUI interaction testing; program testing

Helping Users Shop for ISPs with Internet Nutrition Labels - Sundaresan, Srikanth; Feamster, Nick; Teixeira, Renata; Tang, Anthony; Edwards, W. Keith; Grinter, Rebecca E.; Marshini Chetty; de Donato, Walter (ACM SIGCOMM Workshop on Home Networks '11, 2011)
When purchasing home broadband access from Internet service providers (ISPs), users must decide which service plans are most appropriate for their needs. Today, ISPs advertise their available service plans using only generic upload and download speeds. Unfortunately, these metrics do not always accurately reflect the varying performance that home users will experience for a wide range of applications. In this paper, we propose that each ISP service plan carry a "nutrition label" that conveys more comprehensive information about network metrics along many dimensions, including various aspects of throughput, latency, loss rate, and jitter. We first justify why these metrics should form the basis of a network nutrition label. Then, we demonstrate that current plans that are superficially similar with respect to advertised download rates may have different performance according to the label metrics. We close with a discussion of the challenges involved in presenting a nutrition label to users in a way that is both accurate and easy to understand.
Keywords: access networks; benchmarking; bismark; broadband networks; gateway measurements